The difference between centrifugal force and centripetal force is :

1. they both act in the same direction
2. they both act in opposite direction
3. they both have different magnitudes
4. none of the above

Which of the following is an example of uniform circular motion?

1. a car accelerating on a straight road
2. a pendulum swinging back and forth
3. a satellite orbiting the earth at a constant altitude
4. a ball rolling down a hill

Give one example of motion in which speed remains uniform, but the velocity changes.

Name the force required for circular motion. State its direction.