Suppose that a cart is moving along a road at a constant velocity. Give two examples of ways to cause the cart to decelerate, explaining how the net force is affected.

Answer 1

Two examples of ways to cause the cart to decelerate are applying the brakes and increasing the force of friction.

1. Applying the brakes: When brakes are applied, they increase the friction between the wheels and the road surface. This increased friction opposes the motion of the cart, causing it to slow down. The net force acting on the cart is now in the opposite direction of its velocity, resulting in deceleration.

2. Increasing the force of friction: If an external force is applied on the cart in the opposite direction of its motion, the force of friction between the wheels and the road surface will increase. This increased friction will create a net force opposite to the cart's velocity, leading to deceleration.

In both cases, the net force acting on the cart changes from zero (when it was moving with constant velocity) to a non-zero value in the opposite direction of its initial motion, causing the cart to decelerate.