Physics (AS & A Level) · Oct / Nov 2020 · Paper 13 · Question 10

An object of mass m travelling with speed 5u collides with, and sticks to, an object of mass 5m travelling in the same direction with speed u. What is the speed with which the two objects travel together in the original direction?

1. A\frac{3}{10} u
2. Bu
3. C\frac{6}{5} u
4. D\frac{10}{6} u

As printed in the paper