Motion Masters Reading Sheet
Physical Science Reading
HOW THINGS MOVE: THE THREE LAWS
Learn how Sir Isaac Newton discovered the rules of motion
Name:
Date:
Class:
Score:
Core Vocabulary
Force
A push or a pull on an object.
Energy
The power to do work or make things move.
Motion
Moving from one place to another.
Newtons (N)
The unit used to measure push and pull.
Over 300 years ago, a scientist named Sir Isaac Newton figured out how objects move. He showed that things will not start moving, stop, or change speed without an applied force powered by energy. Whenever something is in motion, Newton's rules explain what happens. To honor him, scientists measure force in Newtons (N).
Newton's Three Simple Rules
Three rules that explain movement
1
First Law: Things Keep Doing What They Are Doing
Inertia
An object that is sitting still stays still. An object that is moving keeps moving at the same speed in a straight line. It will only stop or turn if an outside force pushes or pulls it. This tendency to resist change is called inertia.
Example: A resting soccer ball will never move until a foot kicks it. When a car stops fast, your body slides forward until your seatbelt stops you.
2
Second Law: Heavier Things Need More Force
F = m × a
How fast something speeds up depends on how hard you push it and how heavy it is. A hard push gives more speed than a gentle push. But heavy objects with more mass need more energy and more force (measured in Newtons) to get moving.
Example: It is easy to push an empty shopping cart. But if the cart is full of heavy canned food, you have to use a lot more force to push it forward.
3
Third Law: Action & Reaction
Action-Reaction
For every action, there is an equal reaction in the opposite direction. Forces always come in pairs. When you push against an object, that object pushes back against you with the exact same amount of force.
Example: A rocket blasts hot gas down toward the ground (action). The gas pushes the rocket straight up into the air (reaction).
Part 1: Guided Reading Passage Turn to Page 2 for Questions
Comprehension & Practice
CHECK YOUR UNDERSTANDING
Answer each question in clear sentences.
1
First Law: The Skateboard Bump
Law of Inertia
A rider is coasting on a skateboard. The board hits a curb and stops right away, but the rider's body flies forward. Why does the rider keep moving? Use the word inertia to explain your answer.
2
Second Law: Tennis Ball vs. Bowling Ball
F = m × a
You push a light tennis ball and a heavy bowling ball with the exact same push of 40 Newtons. Which ball will speed up faster? Why does a heavier object need more force to move fast?
3
Third Law: Swimming in a Pool
Action & Reaction
When you swim, your hands push the water backward. What is the action force? What is the reaction force? How does this help you move forward across the pool?
4
Review Question: What Is a Force?
Summary
In your own words, what is a force? What unit do we use to measure force (hint: Newtons)? How does using energy to push or pull an object change its motion?
Part 2: Assessment & Application Page 2 of 2
