The bob of a simple pendulum (mass m and length l) dropped from a horizontal position strikes a block of the same mass elastically placed on a horizontal frictionless table. The K.E. of the block will be :
Answer & explanation
Correct answer: option 1
P.E. of bob at point A = mgl
This amount of energy will be converted into kinetic energy
∴ K.E. of bob at point B = mgl
Since Collision is elastic hence bob will come to rest and block will start moving with speed same as that of bob.
$\Rightarrow \text{K.E of Block will be } mgl$
