Question

What is not an example of Newton's third law?

• A. Rowing a boat in a pond
• B. Walking
• C. Lowering your hands while catching the ball
• D. Firing a bullet from a gun

Answer 1

The correct option is C

Lowering your hands while catching the ball

Explanation of the correct answer:

Option C

Lowering your hands while catching the ball

1. When playing a ball, you prefer to drop your hands since this increases the time it takes to grab the ball, and hence the time it takes to shift momentum.
2. Therefore, a small force is exerted on the hands by the ball.
3. $F=\frac{dP}{dt}WherePismomentum,Fisforce,Tistime$
4. When time is increased, the impact of force is less. This is Newton's 2nd law of motion.
   

Explanation of the incorrect answer:

Option A

Rowing a boat in a pond

1. It is an example of Newton's third law of motion
2. As the boatman pushes the water backward and the water comes forward.
3. The water applied the equal and the opposite force to push the boat.

Option B

Walking:

1. In order to walk, we push our foot against the road and thus exert action force in the backward direction.
2. According to Newton's third law, the ground exerts an equal force in the opposite direction.

Option D

Firing a bullet from a gun

1. It is an example of Newton's third law.
2. It is an example of transitional motion
3. Motion in which a body shifts from one place to another in a straight line
4. When a bullet is fired from a gun, the gun applies forward force to the bullet. This is the force of action.
5. A similar force is applied to the gun by the bullet when it is fired backward. The response force is this. Due to the huge bulk of the gun, it only moves the shooter's shoulder a short distance backward. The term "recoil" refers to the gun's forward movement.

Hence, option C is the correct option.