Homework Help: Physics - Center of Mass

Posted by Ray on Saturday, June 16, 2012 at 7:44pm.

A baseball player uses a bat with mass mbat to hit a ball with mass mball. Right before he hits the ball, the bat's initial velocity is 36 m/s, and the ball's initial velocity is -20 m/s (the positive direction is along the positive x-axis). The bat and ball undergo a one-dimensional elastic collision. Find the speed of the ball after the collision. Assume that mbat is much greater than mball, so the center of mass of the two objects is essentially at the bat.

Physics - Center of Mass - Elena, Sunday, June 17, 2012 at 4:48pm
u=36 m/s, v(o)= -20 m/s.
Imagine that the bat is at rest, and the ball is approaching to it at the releative velocity
v(x)= v(o)+u =20+36 =56 m/s.
Then in the bat’s frame of reference the ball bounces at the velocity 56 m/s directed in opposite direction. The velocity of the ball in the rigid frame is the sum of the relative velocity of the bounce and velocity of the moving frame of reference.
The projections on the x-axis;
v(x) = 2u(x) –v(ox),
u(x) = u.
v(ox) = -v(o) ,

v(x) = 2u+v(o)

Answer this Question

Related Questions

physics - A baseball player puts a baseball on a batting tee. The baseball bat ...
physics - A basketball of mass 0.602 kg is passed to a player of mass 83.0 kg ...
Science: Phsycs - A baseball player swings his 2 kg bat with a speed of 15 m/s. ...
physics - A baseball player pops a pitch straight up. The ball (mass 160 g) was ...
physics - A baseball mass of 150.0g, is thrown by the pitcher toward the home ...
physics- PLEASE HELP - 2. A .12 kg ball is moving at 6 m/s when it is hit by a ...
Physics - A baseball whose mass is 0.25kg is struck by a bat. just before impact...
physics - suppose a major league pitcher can throw a baseball at about 45 m/s (...
physics - as a baseball player strikes the ball with his batt the 1kg bat ...
physics - Is it true that when a baseball player hits a home run, the baseball ...

For Further Reading

First Name:
School Subject:
Answer: