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

d)

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.

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.