What is force?
A force is a ____ or a ____.
Push or pull
What force happens when two surfaces touch and resist motion?
Friction
What is a pattern?
Something that keeps repeating.
What type of force can pull or push without touching?
Magnetism
Who uses knowledge of forces to solve problems and build useful things?
Engineers
When something starts moving, stops, or changes direction, what is involved?
Forces are involved.
Is friction a contact or non-contact force?
Contact force—it occurs between surfaces that are touching.
Give an example of a repeating motion mentioned in the book.
A pendulum swinging back and forth; each swing takes the same time.
What is a magnet?
A material that applies the force of magnetism.
Who was Elijah McCoy?
Elijah McCoy was an engineer and inventor
What two qualities of forces help us predict motion?
Strength and direction.
Why is it harder to walk on ice than on a rough sidewalk?
Ice has little friction; rough surfaces have more friction.
What can we do when we observe regular motion patterns?
Predict the motion.
What does a magnet attract?
Metal objects like those with iron; it doesn’t affect non-magnetic materials like wood, plastic, or water.
Before trains, how did people transport materials?
By foot, by animals, or by boat
What happens when forces on an object are balanced?
They cancel each other out and there is no motion or change.
When a block on a ramp doesn’t move, what forces are at play?
Gravity pulls it down, friction opposes motion, and they are balanced.
At the highest point of a swing, what force acts, and what happens next?
Only gravity acts; the object stops briefly then swings back down.
How do magnets interact with each other?
Like poles repel and opposite poles attract. (E.g., they push or pull each other.)
What causes engines of trains to wear out?
friction and heat
What causes motion when forces are unbalanced?
The stronger force changes the object’s motion.
What does friction oppose?
Motion or potential motion.
What is motion?
A change of position.
What is magnetism?
A force that can push or pull materials without touching them.
To improve how trains work, engineers developed magnetic trains called what?
maglevs