9. A truck is moving toward you at a speed v. Instead of moving out of the way, you decide to throw a tennis ball
at it. The ball has mass m and speed v0. After it hits the front of the truck and bounces (elastically), how fast
is the tennis ball moving with respect to the ground ?
(A) ½v0 v½ (B) v0 + v (C) v0 (D) v0 + 2v
2007-02-12 17:10:51 · 2 answers · asked by mathiphy 2 in Science & Mathematics ➔ Physics
Since it is an elastic collision, that means that all the energy is converted back into the motion of the ball. This means speed of the ball relative to the truck is the same before and after the collision. The ball is moving relative to the truck at a speed of v+v0, and afterwards it is moving relative to the truck at a speed of v+v0 so relative to the ground it is moving at a speed of v +(v+v0) or v0 +2v so the answer is D
2007-02-12 17:21:43 · answer #1 · answered by xit_vono 2 · 0⤊ 0⤋
d why the ball is no mach v0+2v the ball hit moves at a faster speed
2007-02-12 17:42:40 · answer #2 · answered by rocketman 3 · 0⤊ 0⤋