Two balls A and B of masses 100 gm and 300gm respectively are pushed horizontally from a table of height - Physics - Motion In A Straight Line

Question

Two balls A and B of masses 100 gm and 300gm respectively are
pushed horizontally from a table of height 3 meters Ball has is
pushed so that its initial velocity is 10 m/s and ball B is pushed
so that its initial velocity is 15 m/s

a) find the time it takes each ball to hit the ground

b) what is the difference in the distance between the points of
impact of the two balls on the ground?

Pintu B. · Accepted Answer

Dear Student,
(a)Here in this case let the time taken by the balls to fall on
ground is tA and tB respectively
Now,vA2=uA2+2gh           and           vB2=uB2+2gh⇒vA2=100+2×9·8×3        ⇒ vB2=225+2×9·8×3⇒vA=12·6  m                             ⇒vB=16·8 mNow , vA=uA+gtA      and             vB=uB+gtB    ⇒tA= vA-uAg =0·26 sec       ⇒tB= vB-uBg=1·72 sec
So the ball A and B will hit the ground in
0·26 sec and 1·72 sec
respectively
Now to calculate the difference between the distance between point
of impact is
SA=vAtA                            and                   SB=vBtB    =12·6×0·26                                            =16·8×1·72     =3·276 m                                                 =28·896 mSo the difference between the distance their point of impact is,S=SB-SA=25·62 m
Regards