Physics MCQs thread.

[unique840]

How can I solve this?

% contraction is contraction/original lenght*100 = strain*100
fine the area by pie*(d/2)^2
tention/area=stress
stress/young modulus = strain
strain*100=ans

 

[yubakkk]

post ur q. by screen catch or send link

 

[melon159]

what's the answer ????? B???

 

[yubakkk]

which q.???

 

[arlery]

How do we get 12J as the answer?

 

[Betelgeuse]

@arlery..
Look when trolley of mass 2kg moves with 2ms-1 to the left, that shows that trolley of mass 1kg moves to the right with a velocity of 4ms-1 ...
Now add the individual kinetic energies to get 12 joule ..

 

[nidzzz09]

Q 13 http://www.freeexampapers.com/past_pape ... F2009+Nov/

Can yu pls show the steps

 

[Saturation]

I have no idea! why isn't it A?

 

[nidzzz09]

I have no idea! why isn't it A?

Ans : C

but iDk i guess yu luk the other way around

 

[arlery]

@arlery..
Look when trolley of mass 2kg moves with 2ms-1 to the left, that shows that trolley of mass 1kg moves to the right with a velocity of 4ms-1 ...
Now add the individual kinetic energies to get 12 joule ..

How do we know it moves with 4ms-1 to the right?

 

[Saturation]

I have no idea! why isn't it A?

Ans : C

but iDk i guess yu luk the other way around

lol, there has to be a way though..

 

[nidzzz09]

Q 13 http://www.freeexampapers.com/past_pape ... F2009+Nov/

Can yu pls show the steps

 

[nidzzz09]

I have no idea! why isn't it A?

Ans : C

but iDk i guess yu luk the other way around

lol, there has to be a way though..

Rght we somehow thnk alike

 

[Saturation]

@arlery..
Look when trolley of mass 2kg moves with 2ms-1 to the left, that shows that trolley of mass 1kg moves to the right with a velocity of 4ms-1 ...
Now add the individual kinetic energies to get 12 joule ..

How do we know it moves with 4ms-1 to the right?

its the conservation of momentum:

Initial momentum = 0,
final total momentum = 2(-2) + 1(v) = 0
therefore v = 4 (to the right, since I took 2 ms^-1 to the left)

the find the total K.E., and this the energy which was stored in the spring as strain energy.

 

[nidzzz09]

How do we get 12J as the answer?

Find the Speed for the 1 kg trolley

M^1*V^1=M^2*V^2

2kg * 2ms^-1 = !kg* X

You get $4 kgms^-1

No find kinetic energy for the trolley And add them
you get 4+8=12

 

[nidzzz09]

Okay someone help me with my doubt Yallah do it http://www.freeexampapers.com/past_pape ... F2009+Nov/

Question 13

 

[arlery]

which variant ?

 

[Betelgeuse]

How do we post images in this forum?

 

[arlery]

The image should be in png format. Just click on post reply and click upload attachment.

 

[unique840]

I have no idea! why isn't it A?

make a second wave to the right of the original wave. u will see that A is moving down while C is moving upwards