## Exploration 11.2: Nonuniform Circular Motion

In this Exploration you are looking down at a black ball on a table top. Drag the crosshair cursor (position is given in meters and time is given in seconds) to within 5 m of the 0.2-kg black ball. The cursor will then exert a constant force on the black ball. You may choose either an attractive or a repulsive force. In addition, the black ball is constrained to move in a circle by a very long wire. The blue arrow represents the net force acting on the mass, while the bar graph displays its kinetic energy in joules. Restart.

For attraction and repulsion, drag the cursor around to see the net force.

1. At the beginning of the animation (after you press "play" but before you move the cursor), in what direction does the net force point?
2. With this force, does the black ball move? Why or why not?
3. Where must you apply the force in order to make the ball acquire a tangential velocity?
4. Describe the direction of the force that makes the ball acquire the maximum tangential velocity for the force applied.
5. How does the magnitude of the torque relate to the force applied?
6. How does the direction of the torque relate to the force applied?

Physlets were developed at Davidson College and converted from Java to JavaScript using the SwingJS system developed at St. Olaf College.