Two trucks that look the same collide. One was originally at rest. The trucks stick together and move off at more than half the original speed of the moving truck. What can you say about the contents of the two trucks?

Answer 1

the attack truck was heavier :)

If they were the same
m1 * v + m2 *0 = (m1+m2) v final
2 m moves half as fast as 1 m
but if m2 is smal
then
v final approaches v