Question

A ball of mass 5 kg attached to a string is swung in a horizontal circle of radius 0.5 m. If the tension in the string is 10 N, the work done by the tension in one revolution is _____________ J.

Answer 1

The work done by the tension in the string is 0 J, as the tension is always perpendicular to the displacement of the ball moving in a horizontal circle.

Step-by-step explanation:

The question asks for the work done by the tension in a string when a ball is swung in a horizontal circle for one revolution. Work done is defined as the force applied in the direction of the displacement times the displacement itself. As the ball is moving in a circular path, the direction of tension is always perpendicular to the displacement of the ball during its motion. Since work is only done when the force has a component in the direction of the displacement, and in this case that component is zero, the work done by the tension in the string over one revolution is 0 J.

Answer 2

0 J

Step-by-step explanation:

given,

mass of the ball = 5 kg

radius of the horizontal circle = 0.5 m

tension in the string = 10 N

Work done = ?

Work done by the tension in the circular path will be equal to zero.

This is because body moves in circular path, the centripetal force act along the radius of the circle and motion is right angle to the tension on the string.

so, work done = F s cos θ

θ = 90°,

work done = F s cos 90° ∵ cos 90° = 0

Work done = 0 J