Question

Why it is easier to pull a lawn mower than to push it?

Assertion (A) Action and Reaction forces do not cancel out each other. Reason (R) It is because both do not act on the same body.

Assertion (A) Newton's third law of motion is applicable only when bodies are in motion. Reason (R) Newton's third law applies to all types of forces, e.g., gravitational, electric or magnetic forces, etc.

When bodies are in contact, there are mutual contact forces satisfying the third law of motion. The component of contact force normal to the surfaces in contact is called normal reaction. The component parallel to the surfaces in contact is called friction. In the figure, 8 kg and 6 kg are hanging stationary from a rough pulley and are about to move. They are stationary due to roughness of the pulley.