Level 32: One person pulls and one person pushes the same cart uphill. The car didn’t budge. Which of the following pairs of forces is an equilibrium pair?

– The force of the person pulling and the force pushing on the car: these two forces are in the same direction ⇒ not two equal forces.

– The force of the man pulling the cart and the force of the cart pulling him back: two forces applied to two different objects ⇒ are not equal forces.

– The force of the man pushing the cart and the force of the cart pushing him back: two forces applied to two different objects ⇒ are not equal forces.

ANSWER EASY