Question

A box slides across a frozen pond toward the left shore as two children standing on opposite shores pull on the box with ropes. The child on the left shore pulls with a force of 3.0 N, and the child on the right shore pulls with a force of 2.0 N. At a certain instant, the speed of the box is 3.0 m>s.

(a) At that instant, what is the power resulting from each force?
(b) What is the power resulting from both forces?
(c) Do your answers to parts a and b change as the box slides? ⦁⦁

Answer 1

given,

children on left shore pulls the rope by 3 N

Children on the right shore pulls the rope by 2 N

speed of the box = 3 m/s

a) Power = Force x Velocity

Power = 3.0 N * 3

Power = 9 Watt

Power = 2.0 N x 3

Power = 6 Watt

b) Net Force = 3.0 N - 2.0 N = 1.0 N

Net Power = 1.0 x 3 Watt

Net Power = 3 Watt

c) net force is acting on the box and at an instant velocity is given so, when the body moves it will accelerate and velocity will change so, the value of part A and B will also change