Question

two balls A and B of mass 40 g and 50 g are moving at speed of 40 ms-¹ and 30 ms-¹ respectively along a straight line in same direction. If after collision ball-A starts moving with 20 ms-¹ in opposite direction, then what will be the speed of ball-B ?

Answer 1

mass of ball A= 40gm= 40/1000=25 kg

mass of ball B= 50gm= 50/ 1000=20 kg

velocity of ball A= 40 m /s

velocity of ball B= 30 m/ s

m1u1+m2u2=m1v1+m2v2

25*40+20*30 = 25*20+25*v2

0.128 m/s ans