Two persons P and Q are standing 54 m apart on a long moving belt. Person P rolls a round stone towards a person Q with a speed of 9 m/s with respect to belt. If the belt is moving with a speed of 4 m/s in the direction from P to Q. What is the speed of the stone w.r.to an observer on a stationary platform?
Let the distance from P to Q be positive.
Given, speed of the belt, vb = +4 m/s
Speed of the stone w.r.t belt, vs = + 9 m/s
Speed of the stone w.r.t a stationary observer= vs + vb = 9+ 4 = 13 m/s