Question

A tether ball is attached to the top of a vertical pole by a string. The tether ball moves in a circle in the horizontal plane. The string sweeps out the surface of a right circular cone, with the apex of the cone at the top where the string is attached to the top of the pole. Which of the following causes the tether ball to move with uniform circular motion? a. Gravitational force b. Tension in the string c. Vertical component of the tension in the string d. Horizontal component of the tension in the string

Answer 1

The tether ball's uniform circular motion is caused by the horizontal component of the tension in the string, which acts as the centripetal force directing the ball towards the center of its circular path.

Step-by-step explanation:

When a tether ball moves in a horizontal circle in the form of a right circular cone, the movement is called uniform circular motion. The cause of this motion is the horizontal component of the tension in the string. This tension provides the necessary centripetal force that keeps the ball moving in a circle. The gravitational force acts downward and the vertical tension component counteracts gravity, but they do not contribute to the circular motion. Rather, it's the horizontal component of the tension that constantly pulls the ball towards the pole, thus ensuring that the ball follows a circular path in the horizontal plane.

Answer 2

d)

Step-by-step explanation:

The horizontal component of the tension in the string is what causes the tether ball to move with uniform circular motion since this circle is in the horizontal plane and thus the centripetal acceleration of the ball must be also in it, pointing towards the center of the circle. The vertical component of the tension in the string cancels out the gravitational force.