A person gives a shopping cart an initial push along a horizontal floor to get it moving,and then lets go.The cart travels forward along the floor,gradually slowing as it moves.Consider the horizontal force(s)on the cart while it is moving forward and slowing.Which of the following statements is correct?
A)Both a forward and a backward force are acting on the cart,but the forward force is larger.
B)Both a forward and a backward force are acting on the cart,but the backward force is larger.
C)Only a forward force is acting,which diminishes with time.
D)Only a backward force is acting,no forward force.

Question

Quizplus · Accepted Answer

According to Newton's Third Law, for every action, there is an equal and opposite reaction. The force applied by the person initially pushing the cart forward creates an equal and opposite force in the backward direction on the cart. This force acting in the opposite direction is known as friction. As the cart moves forward and slows down, the force of friction continues to act in the opposite direction, gradually reducing the cart's speed. Therefore, only a backward force is acting on the cart, and there is no forward force acting once the initial push has stopped.

A Person Gives a Shopping Cart an Initial Push Along