Question

section 3 review
key ideas

1. state newton’s third law of motion, and give an example that shows how this law works.
2. describe how momentum is calculated.
3. explain what the law of conservation of momentum means, and give an example.

critical thinking

1. evaluating models which of the following models explains why the action and reaction forces don’t cancel each other when a soccer ball is kicked?

a. the force of the player’s foot on the ball is greater than the force of the ball on the player’s foot.
b. the forces do not act on the same object.
c. the reaction force happens after the action force.

1. identifying examples list the action and reaction forces in three force pairs. do not use examples from the chapter.
2. applying ideas the forces exerted by earth and a skier become an action - reaction force pair when the skier pushes the ski poles against earth. explain why the skier accelerates while earth does not seem to move at all. (hint: think about the math equation for newton’s second law of motion for each of the forces.)

math skills

1. calculate the momentum of a 1 kg ball that is moving eastward at 12 m/s.

Explanation:

Step1: Recall momentum formula

Momentum \(p = mv\), where \(m\) is mass and \(v\) is velocity.

Step2: Identify values

Given \(m = 1\ kg\) and \(v=12\ m/s\).

Step3: Calculate momentum

\(p=1\times12 = 12\ kg\cdot m/s\)

Answer:

\(12\ kg\cdot m/s\)