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 ▸Why does an electric drill heat up when passing through metal compared to in thin air?
How and why does a geostationary satellite stay above the same point on the Earths surface?
Give a brief description of the Big Bang and describe its link to cosmic microwave background radiation.
The energy of a photon is 1.5MeV. Calculate the frequency associated with this photon energy and state an appropriate unit in your answer.