Forces and Motion
What is a push or pull called?
Force
What does friction usually do to motion?
Slows it down
What force pulls objects toward Earth?
Gravity
Opposite poles ___, same poles ___.
Attract; repel
Newton’s 1st Law is also called the Law of ____.
Inertia
What law says “objects in motion stay in motion”?
Newton's First Law
Which surface has more friction: carpet or ice?
Carpet
What two factors affect gravitational force?
Mass and Distance
What material do magnets attract?
Iron (also nickel, cobalt)
Newton’s 2nd Law says Force = ____ × ____.
Mass × Acceleration
If you push something with more force, what happens to its acceleration?
It increases
What type of friction happens when an object slides?
Sliding friction
Why do astronauts float in space?
They are in free fall
What creates a magnetic field?
Moving electric charges
Newton’s 3rd Law states: “For every action, there is an equal and opposite ____.”
Reaction
Which has more inertia: a bowling ball or a baseball?
Bowling Ball
Name one time friction is helpful.
Answers vary (shoes gripping floor, brakes, etc.)
Does gravity act only on Earth?
No, every object with mass has gravity
What happens when you cut a magnet in half?
You get two smaller magnets
Give a real-life example of Newton’s 1st Law.
Answers vary (a book stays still until pushed, a soccer ball rolls until friction stops it, etc.)
What two factors affect an object’s acceleration in Newton’s 2nd Law?
Force and Mass
Why do icy roads make cars harder to stop?
Low friction
Why does a bowling ball and a baseball fall at the same rate (ignoring air resistance)?
Gravity accelerates them equally
Why does Earth act like a giant magnet?
It has a molten iron/nickel core
How do brakes use friction to stop a car?
Pads rub against wheels to slow motion