Need Help in Physics As May/June 2015 Variant 2

[madridtas_CR7]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s15_qp_12.pdf
Q.8,Q.9,Q.10,Q.11,Q.12,Q.17,Q.22, Q.23,Q.24,Q.25,Q.26,Q.27,Q.30,Q.32,Q.34,Q.35,Q.36,Q.39,Q.40

 

[abbas haider]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s15_qp_12.pdf
Q.8,Q.9,Q.10,Q.11,Q.12,Q.17,Q.22, Q.23,Q.24,Q.25,Q.26,Q.27,Q.30,Q.32,Q.34,Q.35,Q.36,Q.39,Q.40

Ok i ll answer q from q8 till q17 ( cuz these are the topics i have studied so far ... i apologise )

Q8

answer is D

As the stone is thrown horizontally, the intial velocity of vertical component is 0 m/s ,it goes downwards due to pull of gravity by earth, thus it's vertical component of velocity increases uniformly because of the constant acceleration due to gravity (9.81 m/s^2).

the graph at d starts from origin confirming the fact that the intial velocity of vertical component is 0 m/s

and the gradient of this velocity time graph which is acceleration is constant shown by straight line.

Q9

answer is c

the question can be solved in two parts

part a when accleration is 2.5
part b when speed is constant thus acceleration is 0.

dividing in 2 parts is because to apply equations of motions acceleration must be constant.

in part a
using first law of equation

v= u + at
10 = 0 + 2.5t
t = 4s

now using this time to find distance travelled in 4 sec
2as = v^2 - u^2
2*2.5s = 100
5s= 100
so s = 20m

so runner travels 20 m in 4 sec when there was acceleration
and time for rest of the journey can be found by 100- 20 = 80 m
thus 80 m is travelled at 10/ms
which is 80/10 = 8 sec for part b of journey

total time = 4 + 8 = 12 s

Q10

answer is C

as the engine starts it'produces constant upward force(upthrust)(note: every engine produces constant upward force because there cc's(eg 2000cc engine) are defined ) but since it's fuel burns this means it's mass decreases with time hence acceleration increase with time. which is confirmed by f = ma
the net force F is constant so as m decreases acceleration must increase so that force remains constant.

after 5 sec the fuel gets used up so the mass remains constant ,and upward force is already constant

subsituting these values in f = ma
acceleration remains constant also becuz neither force nor mass are changing thus acceleration ai'nt changing too.

Q11
answer is d
idk why momentem is shared sorry

but we can do it by elimination

a and b are out of the question because momentem and energy are two different quantities ....energy can be converted to energy only
c is incorrect becuz it rejects the idea of principle of conservation of momentem as it is a isolated system which is confirmed by the words friction less.
and so d is the only possible answer moreover when these bodies collide some of kinetic energy is lost of trolley x as it is converted to heat and sound.because it's an inelastic collision confirmed by the fact
that The two
trolleys become attached.

Q12

answer is c

horizontal force is 0 as there's no acceleration ( there is velocity but no acceleration)

vertical force is constant because of constant downward acceleration by gravity of moon

(NOTE FORCE CAUSES ACCELERATION F = MA ... FORCE IS NOT ALWAYS PRESENT WHEN BODY IS MOVING IN SPACE)


Q17
answer is d

total enegy gained is K.E (due to motion of body ) + (potential energy due to height of body )

k.e + p.e
1/2mv^2 + mgh
(1/2 * 0.25 * 1.1^2) + (0.25*9.81*1.8) note unit conversion is must i.e g to kg)

= 4.6j

 

[madridtas_CR7]

 

[madridtas_CR7]

Can anyone solve this question

 

[abbas haider]

Can anyone solve this question

Is The Answer A ? ? ?