A ball A is thrown up vertically with speed u At the same time instant another ball B is - Physics - Motion In A Straight Line

Question

A ball A is thrown up vertically with speed u At the same time
instant another ball B is released from rest at a height h
vertically above the point of projection of A Taking the moment of
projection as t=0 and acc=g find a)At any time t, magnitude of
relative acc of A with respect to B b)The speed of A relative to B
is c)The separation between the bodies Ans is-a)0 b)u c)h-ut

Vara · Accepted Answer

(a)Acceleration of vertically projected body=gAcceleration of freely falling body=gRelative acceleration=g-g                                       =0(b)After 't' seconds:Speed of A=u-gtSpeed of B=-gtSpeed of A relative to B=u-gt--gt                                            =u(c)After 't' seconds:Displacement of A=ut-12gt2Displacement of B from top=12gt2Seperation =h-ut-12gt2+12gt2                      =h-ut