A railway car of mass m1 travelling at a velocity of v1 collides with a second car of mass m2 travelling at v2 and the two join together. What is their final velocity?
Momentum is conserved in any collision, and for a single body is given by p = mv. The momentum before is m1v1+m2v2, and the momentum after is (m1 + m2)u where u is the final velocity, so the final velocity is (m1v + m2*v2)/(m1 + m2).
Related Physics A Level answers
All answers ▸What is the total energy of a spaceship of mass m, orbiting a planet of mass M in a circular orbit with radius r? The ship and the planet are taken to be an isolated system.
A cannon can fire a cannonball at 20m/s. A sandpit is placed at a distance of 40m away. At what angle should the cannon be fired in order for the cannonball to land in the sand.
How to determine the total time of flight for a projectile launched at an angle theta to the horizontal with an initial speed u?
A rock has a mass of 100g and it is thrown across a pond at a speed of 30ms^-1. Calculate the de Broglie wavelength of the rock and explain whether you can see the wave produced.