A 0.3 kg object moving at 8ms^-1 on a friction-less surface collides head on with a 0.5kg object moving in the opposite direction with a velocity of 10ms^-1.
A)What is the velocity of the objects if they stick together after the collision?
B)How much mechanical energy has been dissipated in the collision?

Question

A 0.3 kg object moving at 8ms^-1 on a friction-less surface collides head on with a 0.5kg object moving in the opposite direction with a velocity of 10ms^-1. 
A)What is the velocity of the objects if they stick together after the collision? 
B)How much mechanical energy has been dissipated in the collision?

anonymous · Answer

@douglaswinslowcooper you've been very helpful think you could take a look at this problem?

anonymous · Answer

Thank you.

First, momentum must be conserved:

m1 v1 + m2 v2 = (m1 + m2)(v3)

careful: v1>0 but v2 <0, use correct sign.

Second, energy is lost in inelastic collisions (objects stick together), so calculate the initial kinetic energy by summing (1/2)m v^2 for each at the start and then for (m1+m2) at the end and
compare. Some mechanical KE lost as heat due to deformation, probably.