Question

a body of mass 80 kg moving with 10 m/sec collides with another body of mass 60 kg moving with 20m/sec.if after collision they entangle and continue to move, determine their velocity after collision

Answer 1

momentum = mass * velocity
momentum of 1 body = 80 kg * 10 m/sec
                                   = 800 kg.m/sec


,momentum of 2 body= 60 kg * 20 m/sec
                                   = 1200 kg.m /sec

since, momentum of 2 body is greater it will remain moving in the direction of 2nd body

Answer 2

let the V1 is the velocity after collision

V1
= {(m1 - m2 ) u1 / m1+m2 } + 2m2u2 / m1+ m2

V1= 20 × 10 / 140 + 2× 20×60 / 140
V1 = 200 + 2400 / 140
V1 = 2600 /140
V1 = 18.5 m/s

V2 =(2× 80 × 10 / 140 ) + ( -20 × 20 ) / 140 V2 = 1600 - 400 / 140
V2 = 1200 / 140
V2 = 8.5 m/s