General Thoughts: Physics (4 Viewers)

[Sarah Jane 1]

i did the same and got the same answer

 

[malcolm21]

that was a different question wasnt it, you wouldnt have to derive it
but for the 6 mark space one, it would have been good to explain that orbital & escape velocity are derived from the universal gravitation law

oh alright, do you know why the one im thinking about was worth 3 marks? you literally do it in one line. For that 6 marker did you talk about how the planets are attracted by the sun and orbit it and stuff

 

[p0llex]

What's qV? I equated work and kinetic energy (as work is equal to the change in kinetic energy). So Fs = 1/2mv^2 or qEs = 1/2mv^2. Answer came out to 4.1x10^7

Yep my mistake I got that too, I was thinking about the velocity of the satellite

 

[vflaash]

v=7798 m/s for orbital velocity question
h= 2.5 metres for that wall in projectile motion question ?

 

[Sarah Jane 1]

What about the height of the platform for projectile?

 

[KingDeezy]

Someone pls post the paper

 

[malcolm21]

i think the problem with this test was how vague some questions were in terms of what they were looking for. But I'd assume that's to seperate those who rote learned and those who do actually conceptually understand content



Referring to the last 6 marker of the test



Couldn't you have just found acceleration first through a=f/m, then used it to find final velocity upon hitting anode through v^2=u^2+2a(delta y)

u can, i did that and got his answer, i got 4.2 *10^7, do you know what u got

 

[p0llex]

v=7798 m/s for orbital velocity question
h= 2.5 metres for that wall in projectile motion question ?

Yes to both

 

[jackleung34]

oh alright, do you know why the one im thinking about was worth 3 marks? you literally do it in one line. For that 6 marker did you talk about how the planets are attracted by the sun and orbit it and stuff

need more detail on which question youre referring to. I don't think i wouldve gotten full marks, but I talked about all of Newtowns laws, relating it to slingshot and travelling between planets. Brough in universal gravitational attraction to emphasize sling shot. Hecticlad talked about Vescape and such which I dont think I touched on. They do open alot of avenues interms of relating it to universal gravitation and I don't think many would have been able to include everything listed already

 

[keepLooking]

I fucked up guys. Band 5 would be a complete dream for me. Anyone feeling the same? I was on a tilt during the exam because this exam was quite different from the past papers ._.

 

[malcolm21]

need more detail on which question youre referring to. I don't think i wouldve gotten full marks, but I talked about all of Newtowns laws, relating it to slingshot and travelling between planets. Brough in universal gravitational attraction to emphasize sling shot. Hecticlad talked about Vescape and such which I dont think I touched on. They do open alot of avenues interms of relating it to universal gravitation and I don't think many would have been able to include everything listed already

the one where the satellite was lifted 200km above earth radius, i did v =root/6.67*10^-11 * 6*10^24/(6380000+200000) if i recall correctly, so one line

 

[keepLooking]

the one where the satellite was lifted 200km above earth radius, i did v =root/6.67*10^-11 * 6*10^24/(6380000+200000) if i recall correctly, so one line

Yeah. It was a 3 marker for the a 'simple' orbital velocity calculation.

 

[IamKirby]

I fucked up the orbital velocity question, the single easiest question in the paper.


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[HecticLad]

oh alright, do you know why the one im thinking about was worth 3 marks? you literally do it in one line. For that 6 marker did you talk about how the planets are attracted by the sun and orbit it and stuff

well the escape velocity formula isnt on the datasheet, so if someone one didnt remember it then they would have to derive it which would probably be worth 3 marks
for the 6 mark, i wrote a lot of shit about the launch e.g. thrust, reduced mass from the fuel, escape velocity. i didnt have much time to write about the planets though, i wrote about the inertia of the rocket in space so they dont need to use fuel, and also the calculations needed to slingshot manouver with F=Gm1m2/r

 

[jackleung34]

Yeah. It was a 3 marker for the a 'simple' orbital velocity calculation.

Most calculation questions are extremely formulaic where you have to have equation/sub/correct answer for 2 marks. I think for this one as Vorbital is not an actual equation on the formula sheet, the third mark may me from deriving the equation, where Fc=Fg. If not i have no idea where 3rd mark is RIP

 

[HecticLad]

the one where the satellite was lifted 200km above earth radius, i did v =root/6.67*10^-11 * 6*10^24/(6380000+200000) if i recall correctly, so one line

mfw put the radius at 200000 not 6580000
fml, well the good thing about it being a 3 mark question is that i will most likely still get 2 marks cus i wrote out all my calculations and values and shit

 

[keepLooking]

Most calculation questions are extremely formulaic where you have to have equation/sub/correct answer for 2 marks. I think for this one as Vorbital is not an actual equation on the formula sheet, the third mark may me from deriving the equation, where Fc=Fg. If not i have no idea where 3rd mark is RIP

it was ~ 7700 something right?

 

[jackleung34]

wtf was that copper/ bar magnet graph holy fuck im pretty sure i got like 2/5 marks

it was ~ 7700 something right?

what i got at least

 

[malcolm21]

it was ~ 7700 something right?

i got 7798.76

 

[SlimiJay]

does anyone have the paper who could upload it?