Question

Two persons are applying forces on two opposite sides of a moving cart. The cart still moves at the same speed in the same direction. What do you infer about the magnitudes and direction of the forces applied?

Answer 1

Diagram of the system

The net force acting on the cart:

1. The magnitude of force refers to the sum of all the forces that are acting on an object.
2. If all the forces are acting in the same direction, then the magnitude of the force increases.
3. If the forces are acting on an object in different directions, then the magnitude of the force decreases.
4. According to the first law of motion, a body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it.
5. Since the cart is still moving at the same speed and in the same direction, the forces applied by the persons on the cart will not have any effect on the cart.

Hence, the forces must be applied with the same magnitude, and from opposite directions in order to cancel out the effect of the forces applied.