May 2015- Physics Paper 1 and Paper 2

[Ossih]

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

I put 16 binary states! 

 

Also for the one with finding the induced emf, i started with NBA cos theta but it struck me that it's wrong.

 

The reason is, they ask for the induced emf JUST when the coil is about to completely enter. And so you'd so induced emf = ∆flux/∆t (emf is not NBA cos theta, that's flux ) and you'd find ∆t using suvat equations for free fall. The problem is, that's not the instantaneous change, that's average, that's not specific to when the coil just enters the field.

 

Instead, I did this. I used e = BLv, i said L was the length of one side (cause only one side is moving perpendicular to the field) and v = √2gh because its falling freely, where h is the length of the side. This made sense to me cause thats the instantaneous velocity at the time it just almost completely enters the field! What do you think? 

Edited May 9, 2015 by Ossih

[ordinaryguy]

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

I gave the same answers as you for data analysis and green light emitted, also 16  is the correct answer, then doesnt "s" stand simply for second? anyway i got that wrong haha and I found the grav strength from two mechanics formulas   s = (v+t)2 * t and  v^2 =  u^2 + 2gs

[aa557]

Someone doing SL?

[Megamind]

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

I gave the same answers as you for data analysis and green light emitted, also 16  is the correct answer, then doesnt "s" stand simply for second? anyway i got that wrong haha and I found the grav strength from two mechanics formulas   s = (v+t)2 * t and  v^2 =  u^2 + 2gs

 

I thought that s could stand for second, but then I simply remembered that capacitance involved charge, I didn't remember the whole formula :/ So I disregarded it :/ 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

I put 16 binary states! 

 

Also for the one with finding the induced emf, i started with NBA cos theta but it struck me that it's wrong.

 

The reason is, they ask for the induced emf JUST when the coil is about to completely enter. And so you'd so induced emf = ∆flux/∆t (emf is not NBA cos theta, that's flux ) and you'd find ∆t using suvat equations for free fall. The problem is, that's not the instantaneous change, that's average, that's not specific to when the coil just enters the field.

 

Instead, I did this. I used e = BLv, i said L was the length of one side (cause only one side is moving perpendicular to the field) and v = √2gh because its falling freely, where h is the length of the side. This made sense to me cause thats the instantaneous velocity at the time it just almost completely enters the field! What do you think? 

 

 

I guess it makes sense . 2-3 marks gone ughhh. 

[Guest]

Someone doing SL?

 

Me, TZ1

[FadyR]

TZ2 HL here, For Paper 2- Section B Q8 (on momentum): the Q about Car A and Car B in a box, how'd you guys answer that? I said that energy would be lost as it is transferred through the protective material, time taken for the change in momentum would be longer, and air resistance would decrease the final momentum of the box - which would ultimately all decrease the force that is exerted on car B. 

 

And change in momentum graph- linear line right, with negative gradient and y-intercept at maximum, travelling towards the negative most of the y-axis at x=0.16 seconds or however long the change in momentum took.

 

And with regards to the last sub question, about the length of the DVD in minutes, who else got 118 minutes?

[RandomIBStudent]

Any SL from TZ2? Did anyone pick Q.5 (second question in section B) on SHM and Electrical Currents??

Hi ! Yes I'm SL from TZ2. But I took question 4, not question 5.

 

How did you find the data analysis ?

Edited May 9, 2015 by RandomIBStudent

[karimzahran]

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

That paper 1 question was about expressing capacitance in base units, which would be: charge (C = A s) / voltage (V = J / C) => charge² (A² s²) / energy (J) => A² s² / N m => A² s² / (kg m² / s²) => A² s⁴ / kg m²

[Megamind]

What'd you guys write about the green light one? 

[Eid Jazairi]

SL TZ2 Here!

We reallly need a separate page for SL and HL.. anyways part A for the component parallel to the plane (guy riding the bicycle) was it simply mg sin x? and then mg cos x for the second question? or did I mess up? 

Also, did anyone take number 5 in section B? the last question in the electrical currents part where they asked for the power. It was worth 3 marks but the questions before it required to find the current and gave the voltage and for that question all I did was p=vi, input the given data and get P.. did I do it wrong? was there calculation required? Where are all those 3 marks! Im freaking out! 

For the data analysis, I got slope of 0.82 or something like that, for the y intercept I just extrapolated the graph and found the point which was 1 (I think). and to solve for the x intercept I just used the 0=0.82x+1 which gave me some negative number.. anyone to confirm? 

and for paper one! what did you guys put for the Albedo question /Snow/Ocean/Desert.. and what about the elevator and the weight one? 

[IBdonesoon]

Anyone SL TZ1? I found paper 1 really different and a lot harder than previous exams but paper 2 was a lot easier... I chose question 4.

[Yianni]

Anyone SL TZ1? I found paper 1 really different and a lot harder than previous exams but paper 2 was a lot easier... I chose question 4.

I was time zone 1 SL. Honestly there was a lot of guessing going on there. On paper 1 I mean come on... where were the classic is this a fundamental or derived unit questions... or scalar vs vector quantity... A lot of the questions we did were in higher too, my classmates who are all higher told me (24 hours later 13:00 GMT - just to clarify) that they too had many of our questions. 

As for Paper 2 did you do the environmental that was like an amalgamation of nuclear and wind energy? -Btw that first uncertainty question on the graph was really tough with R and finding the uncertainty of V. Data analysis was far harder this year I felt, the rest was so so. Ugh and that 4 point ice cube question so annoying...

[Sofia.]

 

 

I am TZ2 and I also found Paper 1 challenging, a few questions totally surprised me such as the artificial transmutation or unit for capacitance. Paper 2 was very easy compared to my expectations, I skipped the answers that were worth like 15 marks, the rest I could answer more or less. I had no idea how to solve the last question in section A about magnetic fields, the rest in section A were fine, I picked 6 and 7 in section B. I was planning on doing 7 and 8 but I just started the question number 6 and was like.. oh well. Hope it was a good choice.

 

Not entirely sure I managed to solve the emf question completely, if that's the one you mean. What I did is I used emf = Blv. B was given and the length was the sum of three of the sides (since it had not entered fully, so the last one wasn't in the field as of yet). Since the thing was dropped, the velocity could be found from doing a bit of mechanics, with s = length of one end, u = 0 and a = gravity. Then you can use v^2 = u^2 + 2as to find the velocity. 

 

 

Sofia, Weren't we supposed to use the formula EMF = BAN cos theta, where B is the magnetic field, A is the area, and N = no of turns = 1 (as given) and cos theta = 1. Area = length squared and B is the magnetic field strength. That's what I used at least. 

 

 

Maybe, haha! Sounds easier than my way... I'll just hope that I got the same answer hehe. 

[Sofia.]

 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

I gave the same answers as you for data analysis and green light emitted, also 16  is the correct answer, then doesnt "s" stand simply for second? anyway i got that wrong haha and I found the grav strength from two mechanics formulas   s = (v+t)2 * t and  v^2 =  u^2 + 2gs

 

I thought that s could stand for second, but then I simply remembered that capacitance involved charge, I didn't remember the whole formula :/ So I disregarded it :/ 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

I put 16 binary states! 

 

Also for the one with finding the induced emf, i started with NBA cos theta but it struck me that it's wrong.

 

The reason is, they ask for the induced emf JUST when the coil is about to completely enter. And so you'd so induced emf = ∆flux/∆t (emf is not NBA cos theta, that's flux ) and you'd find ∆t using suvat equations for free fall. The problem is, that's not the instantaneous change, that's average, that's not specific to when the coil just enters the field.

 

Instead, I did this. I used e = BLv, i said L was the length of one side (cause only one side is moving perpendicular to the field) and v = √2gh because its falling freely, where h is the length of the side. This made sense to me cause thats the instantaneous velocity at the time it just almost completely enters the field! What do you think? 

 

 

I guess it makes sense . 2-3 marks gone ughhh. 

 

 

Why only one side? Supposedly all of it is cutting the field at an angle of 90. I did the same as you did, but with three sides instead of just one. 

[IBdonesoon]

 

Anyone SL TZ1? I found paper 1 really different and a lot harder than previous exams but paper 2 was a lot easier... I chose question 4.

I was time zone 1 SL. Honestly there was a lot of guessing going on there. On paper 1 I mean come on... where were the classic is this a fundamental or derived unit questions... or scalar vs vector quantity... A lot of the questions we did were in higher too, my classmates who are all higher told me (24 hours later 13:00 GMT - just to clarify) that they too had many of our questions. 

As for Paper 2 did you do the environmental that was like an amalgamation of nuclear and wind energy? -Btw that first uncertainty question on the graph was really tough with R and finding the uncertainty of V. Data analysis was far harder this year I felt, the rest was so so. Ugh and that 4 point ice cube question so annoying...

Ikr! The paper one had some really obscure questions that I hadn't seen before... especially in fields and magnetism...

 

For paper 2 the data analysis was tough but at least it was short.... so I'm praying for the markbands   

 

Ya I did the environmental question.. it wasnt too bad so I was happy with that. What option did u choose?

Edited May 9, 2015 by IBdonesoon

[Sofia.]

 

again to those who did thermodynamics, there was this last question saying that in adiabatic change work done was i think 210J, what was the change in internal energy.. so since that was adiabatic there was no heat exchange so the change in internal energy was -210J, did i get this one right?

 

Yep, just used the first law of thermodynamics for that one.

Q = 0, Q=dU+W, W=210, -210=U

 

 

Damn, I really can't read the questions carefully. I somehow skipped the adiabatic part hehe... And here I've been thinking P2 went well. 

I somehow got Q to 1300 something? Can't even remember how I got that!

[Ossih]

 

 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

I gave the same answers as you for data analysis and green light emitted, also 16  is the correct answer, then doesnt "s" stand simply for second? anyway i got that wrong haha and I found the grav strength from two mechanics formulas   s = (v+t)2 * t and  v^2 =  u^2 + 2gs

 

I thought that s could stand for second, but then I simply remembered that capacitance involved charge, I didn't remember the whole formula :/ So I disregarded it :/ 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

I put 16 binary states! 

 

Also for the one with finding the induced emf, i started with NBA cos theta but it struck me that it's wrong.

 

The reason is, they ask for the induced emf JUST when the coil is about to completely enter. And so you'd so induced emf = ∆flux/∆t (emf is not NBA cos theta, that's flux ) and you'd find ∆t using suvat equations for free fall. The problem is, that's not the instantaneous change, that's average, that's not specific to when the coil just enters the field.

 

Instead, I did this. I used e = BLv, i said L was the length of one side (cause only one side is moving perpendicular to the field) and v = √2gh because its falling freely, where h is the length of the side. This made sense to me cause thats the instantaneous velocity at the time it just almost completely enters the field! What do you think? 

 

 

I guess it makes sense . 2-3 marks gone ughhh. 

 

 

Why only one side? Supposedly all of it is cutting the field at an angle of 90. I did the same as you did, but with three sides instead of just one. 

 

I thought long and hard about it whether all of it was cutting the field at an angle of 90º. I mean technically, the horizontal side is the only one cutting the field for sure at right angles. The vertical ones, well wouldn't it theoretically depend on how strong the field as (and hence how close the field lines are, so is the wire just in a gap between two field lines). It was quite a weak field, it was in mT. Also if the thickness of the wire was quite thin, same thing, it could be between the field lines and hence not really cut it. Because of this uncertainty, I went with what I was sure of, that one of them cut the field for sure. I hope they give credit for both :/

[Sofia.]

 

 

 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

I gave the same answers as you for data analysis and green light emitted, also 16  is the correct answer, then doesnt "s" stand simply for second? anyway i got that wrong haha and I found the grav strength from two mechanics formulas   s = (v+t)2 * t and  v^2 =  u^2 + 2gs

 

I thought that s could stand for second, but then I simply remembered that capacitance involved charge, I didn't remember the whole formula :/ So I disregarded it :/ 

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

I put 16 binary states! 

 

Also for the one with finding the induced emf, i started with NBA cos theta but it struck me that it's wrong.

 

The reason is, they ask for the induced emf JUST when the coil is about to completely enter. And so you'd so induced emf = ∆flux/∆t (emf is not NBA cos theta, that's flux ) and you'd find ∆t using suvat equations for free fall. The problem is, that's not the instantaneous change, that's average, that's not specific to when the coil just enters the field.

 

Instead, I did this. I used e = BLv, i said L was the length of one side (cause only one side is moving perpendicular to the field) and v = √2gh because its falling freely, where h is the length of the side. This made sense to me cause thats the instantaneous velocity at the time it just almost completely enters the field! What do you think? 

 

 

I guess it makes sense . 2-3 marks gone ughhh. 

 

 

Why only one side? Supposedly all of it is cutting the field at an angle of 90. I did the same as you did, but with three sides instead of just one. 

 

I thought long and hard about it whether all of it was cutting the field at an angle of 90º. I mean technically, the horizontal side is the only one cutting the field for sure at right angles. The vertical ones, well wouldn't it theoretically depend on how strong the field as (and hence how close the field lines are, so is the wire just in a gap between two field lines). It was quite a weak field, it was in mT. Also if the thickness of the wire was quite thin, same thing, it could be between the field lines and hence not really cut it. Because of this uncertainty, I went with what I was sure of, that one of them cut the field for sure. I hope they give credit for both :/

 

 

I don't think it should matter, but hopefully they'll give marks for both. We'll both score some marks, at least

[Sofia.]

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

We got the same gradient, and I think my intercept was 0.92.

For question 6, I used g = F/m, but since the force is also ma, g = ma/m = a. Not sure that was correct, though. Then I simply did the calculation - found the needed escape speed, and compared it to the speed of the rocket. Also got that it couldn't escape, at least. 

[Megamind]

 

In the data analysis question, I got my slope around 1 and the y intercept aro0und 0.97. Anyone else? Also, when you took out the x intercept by equation y=mx + c to zero, did anyone find the value of x weird? Because I got some -0.98 or something and by observing and extrapolating the graph mentally to the minus x axis, it didn't look more than a -0.10. Did anyone get L as 0.93??

 

In paper 1 (Tz2) there was a question about green light being emitted from two point sources which was just NOT resolved. So the question asked how to resolve it and there were two plausible options: use red light (higher wavelength so bigger theta) and use a circular aperture (again bigger theta since 1.22 is there instead of 1). What'd you guys write? I chose red light. 

 

Ossih, what did you write for the possible binary states? 15 or 16? 

 

I had no idea what the "s" in capacitance meant, so I had to skip that question . I mean I knew it was the Farad but I forgot the definition :/ and in all my years of Physics, I have never seen a freaking s as a fundamental unit . Randomnly ticked something and probably got it wrong. 

 

In Paper 2 (tz2), for question 6, everyone found the gravitational field strength as Del V/ Del T right? And therefore from the calculation the rocket cannot escape without further engine use. 

 

Sorry about the blast of questions in your face, I'm just too excited to know everybody's else's answers . 

Also, any other Paper 1 questions anyone found challenging? I keep forgetting :/ 

 

We got the same gradient, and I think my intercept was 0.92.

For question 6, I used g = F/m, but since the force is also ma, g = ma/m = a. Not sure that was correct, though. Then I simply did the calculation - found the needed escape speed, and compared it to the speed of the rocket. Also got that it couldn't escape, at least. 

 

 

But Sofia, I believe this particular formula and your final answer g=a would only apply if the spaceship was on the surface of Earth itself. Over here, we have a spaceship that is far away from an unknown planet, therefore I think a = change in velocity over change in time = gravitational field strength should apply here. This came to around 2.7 m/s squared. However, escape velocity still was not achieved in either case.