Recent content by kappakeepo

Well. Since both bodies have no acceleration(no horizontal force), then the centre of mass of both bodies must have a=0. Also V of com is moving right. The collision occurs at the final centre of mass obviously.

Yes but I think my professor wants me to do this question using centre of mass thinking or momentum thinking or both. But I'm not sure using laws of energy is a must here.

Well. There's no horizontal force obviously since a = 0. Since it is in motion, there has to be kinetic energy and momentum (relative to that frame of reference to be exact)

I'm thinking centre of mass might be relevant here but I don't know how. It's a gut feeling. Also definitely F=-kx during collision. During the collision, momentum from the left mass is transferred to the right mass. I believe this is an elastic collision.

Homework Statement A block of mass m1 slides along a frictionless table to the right with a speed of v1. A second mass M2 slides in the same direction with a speed of v2 such that it will collide with m1 which is in front of m2. Say that a spring of stiffness k is attached to one of the masses...

Thanks for your reply. $$\vec r_{bg} = (\vec u_{cg}t)\hat\imath + (\vec u_{bc}t - 0.5gt^2)\hat\jmath$$ My only question is how do I solve the part "How much time is the ball in the air according to the man on the ground?" I can't let $$\vec r_{bg} = 0$$ because that would be wrong obviously...

Homework Statement A freight train is moving at a constant speed of 10 m/s. A man standing on a flatcar throws a ball into the air and catches it as it falls. Relative to the flatcar, the initial vellocity of the ball is 15 m/s straight up. a. What are the magnitude and direction of the...