multiple choice (1 Viewer)

[Muzzy]

we'll never know the answer!!

 

[Muzzy]

when the BOS RELEASE ANSWERs?

 

[grimreaper]

when the BOS RELEASE ANSWERs?

well... yeah. but thatll be a few months away unfortunately =\

 

[mojako]

6 is D IMO.
its like a projectile..
ball drops with constant downwards acceleration
train moves with constant horizontal velocity.. from the train its like throwing the ball to the opposite direction
note: I havent read the other posts for your arguments btw.. too long

12... I put A for some reason... couldnt decide between A and B

the rest are straight forward

 

[lucyinthehole]

i just realised i made the stupidest mistake, i knew the right answer, but i coloured in the wrong circle. i'm so disappointed. every mark is precious for me in this one, didn't really go that great...

 

[boz]

that means i got 12/15. Shit i thought i was going to get 14 or 15

 

[imafail]

6 is B...think about it when you throw something out your car window while travelling at the speed limit (which we all do) it never moves straight down it always goes behind us and we never see it moving in a parabola so it must be B

 

[somborac]

thats because there is air resistance, in this case air resistance is ignored thus the ball keeps having the same momentum as the car till it touches the ground, thus the answer is C

 

[Cactus]

6 is B...think about it when you throw something out your car window while travelling at the speed limit (which we all do) it never moves straight down it always goes behind us and we never see it moving in a parabola so it must be B

Yes but the question said "Ignore air resistance" and what you have descibed is the effect of air resistance on an object

 

[cephren]

...well i suggest we 4get it... all i kno is im 12-15 marks closer to a pass... thats all i give a shit about... oh and the vast greatness of bourbon and galliano in wait after Ancient History tomorrow... good times... good times...

...though after saying that... can I get an explanation of 12... I 4got we did F Ideas to I...

 

[grimreaper]

6 is B...think about it when you throw something out your car window while travelling at the speed limit (which we all do) it never moves straight down it always goes behind us and we never see it moving in a parabola so it must be B

erm but the frame of reference is accelerating not "sticking to the speed limit" in this case. However, I still believe the answer is B even though I put D

 

[Gesus]

1b 2a 3d 4b 5a 6d 7a 8c 9a 10a 11c 12b 13a 14b 15b
and yes, i realise i got 6 wrong, i should have ruled cause i knew that they werent supposed to be equally spaced, but it didnt look like they were in the test!!!

 

[gordo]

its over who cares wats wat
enjoy the stress free life ppl

u don;t even know, maybe the bos will have multiple answers cause of stupid wording for alot of them

enjoy the serenity of not caring

...
i'm off to study history extn now

 

[SeDaTeD]

Wow so much debate over one question, but i'll add my 2 cents. I was spending ages trying to picture the physics of it, but that got too hard so i turned to good old maths. For q6, I did it the same way as laurie, let x_double_dot = k, y_double_dot=-g, ==> x_dot = kt, y_dot = -gt ==> x = 1/2 kt^2 , y = -1/2 gt^2. Eliminate the parametric and you get y = -gx/k, which is linear, therefore the answer is B.
And i also got 1.8 x 10^-7 for that magnetic constant k thing.

 

[Shuter]

Ok, here is correct answers (my dad is a physics teacher).


1) B [haha I typoed, it was meant to be B not A!]
2) A
3) D
4) B
5) A
6) B
7) A
8) C
9) A
10) A
11) [screwed question] maybe be c or d
12) B
13) A
14) B
15) B

 

[Jase]

haha gee I hope so, i put A for 1... wasn't thinking.

 

[Li0n]

FINALLY someone puts 1 A. how in the hell is it B the question bloody tells you max height is same yet range is double. THAT INSTNALTY TELLS YOU THAT ONE HAS MORE TIME THAN THE OTHER.

 

[paztaboy]

i put a for q1 aswell but its wrong. think about it. if you threw a ball to a certain height and then you threw it to the same height but further. obviously you have to throw it harder?

 

[kunny funt]

FINALLY someone puts 1 A. how in the hell is it B the question bloody tells you max height is same yet range is double. THAT INSTNALTY TELLS YOU THAT ONE HAS MORE TIME THAN THE OTHER.

horizontal motion is independant of vertical motion, so it doesnt matter if the ranges are different.

the fact is that the angles of projection were different which clearly tells u their initial velocities are different (because velocity isnt't just speed but direction too) and that vertical initial velocity was the same, but horizontal different which was the cause of the difference in range.

so, by just looking at the difference in angles u can see it is B and not A

 

[matt_f64]

for 4 i got (c)

8\squareroot of 1-0.6

= 8\square root of 0.4
=12.6

as for 6 its DEFINATELY a)
since when theres no air resistance it will keep the same horiizontal velocity of the vehicle

no. its 8/ square root of 1- 0.6squared/1squared
0.6 x 0.6 is 0.36,
1-0.36 is 0.64
square root of 0.64 is 0.8
8 / 0.8 = 10