An object of 2kg moving at 3m/s hits a 4 kg stationary object, causing the stationary object to begin moving at 0.5m/s. How fast is the original object now travelling?
It is an elastic collision.
Not really sure, 1/2mv^2 I presume.
The Attempt at a Solution
None so far, I'm stuck on it and am not sure how to approach it.