If a 10 lb object and a 50 lb object collide head on at 10m/s, does it matter which object has the velocity ?

Question

Is there a difference in impact if the heavier or the lighter object carries the velocity?

Answer 1

yes, the heavier object will have more momentum, and thus more force.

in regards to above, if you take the two objects as a system, and track the instantaneous center of gravity (CG) of the system, then it doesn't matter which oject has the velocity.

Answer 2

No. This applies at relativistic velocities as well as at the velocities encountered in everyday experience. The famous Michelson-Morley experiment was designed to detect differences in the speed of light with direction, as would be expected if light were traveling through an "ether," which would constitute a frame of reference for absolute motionlessness. Light would appear to travel faster or slower, depending on whether the observer were traveling in the opposite direction as the light or in the same direction through this ether. The failure to detect these ether currents came as a big surprise and forms one of the assumptions of Einstein's Special Theory of Relativity: you will get substantially the same results regardless of how the experimental frame of reference is moving with the observer (or the observer moving with the experiment) as long as neither the observer nor the experiment is being accelerated.

Answer 3

No. It is the relative velocity which counts.