A body of mass 2kg is travelling in a straight line along the x-axis. It collides with a second body of mass 3kg which is moving at -2m/s. The two bodies move off together at 3m/s. What is the initial velocity of the first body?

2u-32=53=15, 2u=15+6. Therefore, u=10.5m/s. This is a standard type of question, it is simply about conservation of momentum. Momentum (p) is equal to massvelocity. Initially, the first body has momentum 2u kgm/s as its mass is 2kg and its velocity is u. The second body has momentum -6 kgm/s. After the collision, the two bodies move off together at the same speed so the final momentum is 15 kgm/s. We can then rearrange to find u.

Answered by Caroline L. Physics tutor

2612 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What is a standard candle?


Calculate the flight time of a ball moving in parabolic motion, with initial velocity 5.0m/s at angle 30 degrees from the horizontal travelling for 23 metres.


Explain the change of quark character associated with the beta-plus decay and deduce the equation.


Describe Newton's second law.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences