1. The problem statement, all variables and given/known data Problem 2 (35 points): A projectile of mass mA=20g is shot towards a block of mass MB= 5kg with a velocity of vA=400m/s. The block is at rest, attached to a horizontal massless spring (at equilibrium) with k=500N/m. a. If the collision between the projectile and the mass is perfectly elastic, what are the velocities of the two masses immediately following the collision? 2. Relevant equations U(x)=1/2kx^2 F=ma Conservation of momentum M1U1 + M2U2 = M1V1 + M2V2 When U is equal to the velocity before the impact. 3. The attempt at a solution I would have a good idea on how to do this problem without the spring being there but with it there i can not figure out how to do it. I know that the total velocities after the collision needs to combine to make 400 but other than that i am pretty lost on this one.