posted by Luke .
A 2.90 kg mud ball has a perfectly inelastic collision with a second mud ball that is initially at rest. The composite system moves with a speed equal to one-third the original speed of the 2.90 mud ball. What is the mass of the second mud ball?
You must be having an identity crisis. Five of the six physics questions you posted have different names.
Please use the same name for all of your posts.