Question

A boy of mass 50 kg running at 5 m/s jumps on to a 20 kg trolley travelling in the same direction at 1.5 m/s. What is their common velocity ?​

Answer 1

Answer:

Boy information

Mass = 50kg

Velocity = 5m/s

Trolley information

Mass = 20 kg

Velocity =1.5 m/s

so using conservation law of momentum

MV+mv=(M+m)Vv

50*5+20".5=(50+20)V'

250+30=70V'

280=70V'

so V' = 4m/s which is their common velocity.

Answer 2

Answer:

v=250+30/7 =4 m/s

Step-by-step explanation:

Mass of the boy, m1 = 50 kg Speed of boy, u1 = 5 m/s Mass of trolley m2 = 20 kg Speed of trolley u2 =1.5 m/s Combined mass of boy and trolley, m = 20+ 50 = 70 kg Combined velocity v Acc. to the law of conservation of momentum m1 u1 + m2 u2 = mv 50 x 5 + 20 x 1.5 = 70 x vRead more on Sarthaks.com - https://www.sarthaks.com/120736/boy-mass-running-jumps-trolley-travelling-the-same-direction-what-their-common-velocity