Vocabulary
What is a force?
A push or a pull on an object.
What kind of force acts at a distance (no touching)?
Magnetic, electric, or gravitational forces.
Balanced forces cause what?
No movement or constant speed.
When two objects collide, what is transferred?
Energy.
A 10 N force pushes left and a 10 N force pushes right. What type of force is this?
Balanced.
What are balanced forces?
Equal forces acting in opposite directions that cause no change in motion.
What does an electric field do?
It pushes or pulls on charged objects around it.
What happens when forces are unbalanced?
The object changes motion (speed up, slow down, or change direction).
A fast ball hits a still ball and the still ball moves. Why?
Energy was transferred during the collision.
A magnet is near wood and iron. Which feels the magnetic force?
Iron.
Define electric charge.
A property of matter; can be positive or negative.
Opposite magnetic poles do what?
Attract.
A box has 10 N left and 5 N right. Is this balanced or unbalanced?
Unbalanced (net force 5 N left).
Stronger force during a collision causes what?
A bigger change in motion.
A scooter has 30 N forward and 10 N friction backward. What is the net force?
20 N forward.
What is a magnetic field?
The invisible area around a magnet where magnetic force acts.
If field lines are close together, what does that mean about the force?
The force is stronger.
What is acceleration?
A change in speed or direction.
Which two things affect the outcome of a collision?
Mass and speed.
If an object speeds up, what must have happened?
An unbalanced force acted on it.
What is net force?
The total of all forces acting on an object.
A positive charge is near a negative charge. What will happen?
They will attract.
What force always opposes motion?
Friction.
If a moving object hits another and slows down, where did its energy go?
Into the other object.
Why do objects feel stronger electric or magnetic forces when closer together?
Because field strength increases with proximity.