Question

A very smart $3$-year-old child is given a wagon for her birthday. She refuses to use it. “After all,” she says, “Newton’s third law says that no matter how hard I pull, the wagon will exert an equal but opposite force on me. So I will never be able to get it to move forward.” What would you say to her in reply?

Short answer

Yes, the wagon will move forward without any hinderance.

Step-by-step solution

Given information

A very smart $3-$year-old child is given a wagon for her birthday.

Explanation

According to Newton's third law of motion, every action has an equal and opposite reaction.

So, you can tell your child that when you push the wagon, it applies equal force on your hand in the opposite direction . This force acts on the hand . Force applied on the wagon will show its effect and wagon will move forward without any hinderance provided there is absence of frictional force.

Final answer

The force that acts on hand in backward direction will be balanced by frictional force of the ground on the body . So hand will not move in backward direction. Only wagon will move forward as you push the wagon .