A) \[2mgl\]
B) \[mgl/2\]
C) \[mgl\]
D) 0
Correct Answer: C
Solution :
Initial potential energy of the bob when its string is horizontal\[=mgl\] This is also the kinetic energy of the bob just before it strikes the block. Since, mass of the block is same as that of the bob and\[{{u}_{2}}=0\], this becomes the case of exchange of velocities, \[i.e.,\] after the collision, the velocity of the bob becomes zero and the block starts moving with the velocity of the both just before the collision. Thus, kinetic energy of the bob just before the collision\[=\] kinetic energy of the block just after collision\[=~mgl\].
You need to login to perform this action.
You will be redirected in
3 sec
