A ball on a 1.4-meter long string is being whirled in mid-air in a horizontal circle at a constant speed v. The tension in the string is 100 N. The mass of the ball is 3.70 kg.

Let's start drawing the free-body diagram for this situation. There's a force of gravity, mg, directed down, and a tension, pointing away from the ball along the string.

Which of the following forces, in addition to tension and the force of gravity, also belong on the free-body diagram?

1. Normal force, directed vertically up. (1/35) (3%)
2. Centripetal force, directed toward the center of the circle. (2/35) (6%)
3. Centripetal force, directed away from the center of the circle. (0/35) (0%)
4. Both 1 and 2 (1/35) (3%)
5. Both 1 and 3 (0/35) (0%)
6. None of the above (30/35) (89%)