# Physics lab: thought lab energy changes

1. Oct 9, 2005

### r3dxP

A childs toy consists of a base that is clamped firmly to a table, a spring and launching ramp attached to the base, and a ball. By compressing the spring, the child can launch the ball up a ramp to fire it off the table. The spring has a spring constant k, the ball has a mass m, and the ramp rises a height h. The spring is compressed a distance (change r) in order to launch the ball. When the ball leaves the launching ramp, its velocity makes an angle Q with respect to the horizontal.

A) Assuming that friction+air resistance can be ignored for the purpose of this problem, describe the changes in the forms of energy in the system from the time the spring is compressed until the ball hits the ground.

B)Calculate the vector velocity of the ball when it leaves the launching ramp. Be sure to specify your coordinate system.

C)The spring constant is 32N/s, the springs compression is 5.0cm, the balls mass is 20g, the height of the ramp is 10cm, and the top of the table is 1.0m above the floor. With what speed will the ball hit the floor?

Any help will be appreciated. Thanks in advance..~

2. Oct 9, 2005

### lightgrav

well, while the spring is being compressed, Chemical Energy is being transformed by Force and movement in the muscles into elastic Potential Energy in the spring. What happens next?

Just as with the functional forms of the various Forces -
you have to practice with the functional forms of the Potential_Energies, or you won't get good at using them. Which forms do you know by now?