A stone of mass 0.1 kg is dropped from the window of a train accelerating at 1 m/s². What is the mag

Question

A stone of mass 0.1 kg is dropped from the window of a train accelerating at 1 m/s². What is the magnitude of the net force acting on the stone just after it is dropped? (Neglect air resistance, g = 10 m/s²)

Professor PC Thomas Classes · Answer

Once dropped, the stone is no longer in contact with the train. The horizontal force becomes zero (ignoring air resistance). The only force acting on it is gravity, $F = mg = 1$ N downwards.