Why is it easier to pull a lawnmower than to push it?
Correct: D
When pulling a lawnmower, the upward component of the pulling force reduces the normal force exerted by the ground on the lawnmower. Since frictional force is directly proportional to the normal force, a reduced normal force leads to reduced friction, making it easier to pull. Conversely, when pushing, the downward component of the pushing force increases the normal force, thus increasing friction.