Question

A stone dropped from a window reaches the ground in 0.5 seconds -

An object of mass 20 kg is sliding with a constant velocity of 4 m/s on a frictionless horizontal surface. The force required to keep the object moving with the same velocity is-

Attempt either (I) with all sub parts or (II) with all sub parts from the following two questions-

Attempt either (I) with all sub parts or (II) with all sub parts from the following two questions-