Question

it is not uncommon during the service of a professional tennis player for the racquet to exert an average force of 150.0 n on the ball. if the ball has a mass of 0.060 kg and is in contact with the strings of the racquet for 0.030 m, what is the kinetic energy of the ball as it leaves the racquet? assume the ball starts from rest.

Answer 1

The work done on the tennis ball by the racquet is the product of the force applied and the distance over which the force is applied. Given a force of 150.0 N and a distance of 0.030 m, the work done and thus the kinetic energy of the ball as it leaves the racquet is 4.5 Joules.

Step-by-step explanation:

To determine the kinetic energy of a tennis ball as it leaves the racquet, assuming that the ball starts from rest, we can use the work-energy principle. The work done on the ball by the racquet is equal to the kinetic energy of the ball just after it leaves the racquet.

The work W is the product of the force F exerted by the racquet on the ball and the distance d over which the force is applied, which can be expressed as W = F * d.

Given:

• Force F = 150.0 N
• Distance d = 0.030 m
• Mass of ball, m = 0.060 kg

So the work done W is:

W = F * d

W = 150.0 N * 0.030 m

W = 4.5 J

Therefore, the kinetic energy KE of the ball when it leaves the racquet is 4.5 Joules, because the work done on the ball goes into its kinetic energy as it starts from rest and is equal to the kinetic energy.

Answer 2

The kinetic energy of the tennis ball as it leaves the racquet, with a mass of 0.060 kg and an average force of 150.0 N applied over a distance of 0.030 m, is 4.5 joules.

Step-by-step explanation:

The student's question is related to calculating the kinetic energy of a tennis ball after being hit by a racquet.

To find the kinetic energy, we can use the work-energy principle, which states that the work done by the forces on the ball will result in a change in kinetic energy.

The work done by the racquet on the ball can be calculated using the formula W = F × d, where W is the work, F is the average force exerted, and d is the distance over which the force is applied.

Knowing the work done and that the ball starts from rest, we can deduce that the work done on the ball is equal to its kinetic energy just after being hit by the racquet.

Given that the average force exerted by the racquet is 150.0 N and the contact distance is 0.030 m, the work done on the ball can be calculated as: W = 150.0 N × 0.030 m = 4.5 J.

Hence, the ball will have a kinetic energy of 4.5 joules as it leaves the racquet.