A block of weight \( 4 \mathrm{~kg} \) is resting on a smooth horizontal plane. If it is struck ...

A block of weight \( 4 \mathrm{~kg} \) is resting on a smooth horizontal plane. If it is struck by a jet of water at the rate of \( 2 \mathrm{kgs}^{-1} \) and at the speed of \( 10 \mathrm{~ms}^{-1} \), then the initial acceleration of the block is
[Kerala PET 2012]
(a) \( 15 \mathrm{~ms}^{-2} \)
(c) \( 2.5 \mathrm{~ms}^{-2} \)
(d) \( 1 m s^{-2} \)
(e) \( 5 \mathrm{~ms}^{-2} \)