Question

discovering newton’s third law of motion
ps unit 2: newton’s laws
name_o’lexla smart
date_11/17/25_hour_7th
part 1: warm up
answer the following questions to review what you know about newton’s first and second laws of motion.
(1 pt each)

1. in your own words, state newton’s first and second laws of motion.
2. while riding a bicycle, you fly forward off the bike when hitting a curb or other object that quickly stops

the motion of the bicycle. explain why this happens using newton’s first law of motion.

1. ted applies a 45 - newton force to a soccer ball at rest causing it to move forward into the goal. the ball

flies forward into the goal. explain why this happens using newton’s second law of motion.

Explanation:

1. Newton's First Law (Law of Inertia): An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Newton's Second Law: The acceleration of an object is directly proportional to the net force acting on it, inversely proportional to its mass (\(F = ma\)).
2. When riding a bicycle, you and the bike are in motion. When the bike hits a curb (an unbalanced force acts on the bike), the bike stops. But your body (due to inertia from Newton's First Law) wants to keep moving forward as it was before the force acted on the bike.
3. According to Newton's Second Law (\(F = ma\)), when Ted applies a force (\(F = 45N\)) to the soccer - ball (which has mass \(m\)), the ball accelerates (\(a=\frac{F}{m}\)). Since the ball was at rest (\(initial\ velocity = 0\)), this acceleration causes it to move forward into the goal.

Answer:

1. Newton's First Law: Objects resist changes in motion. Second Law: Force causes acceleration ( \(F = ma\) ).
2. Your body continues moving forward (inertia - First Law) when bike stops.
3. Force (45N) causes acceleration ( \(a=\frac{F}{m}\) - Second Law) of the ball.