A metallic bob X of mass m is released from position A. It collides elastically with another identical bob Y placed at rest at position B on a horizontal frictionless table. The angle AOB is 30°.

How high does the bob X rise immediately after the collision?

Consider the two statements given below:

Statement-1 : Infrared waves are also called heat waves.

Statement-2 : Water molecules readily absorb infrared waves.

Select the correct answer using the code given below :

If the block P as shown in the figure below were to be at rest, what should the magnitude of force F be?

Of the following, which does not belong to a nuclear reactor?