Definitions
Forces
Gravity
Fricton
True or False
100
Define force
A push or pull interaction between two objects
100
State the unit of measurement for force
Newton (N)
100
When will gravity be the strongest?
A. The further away you are from an object
B. The closer you are to an objecT
C. The faster your relative speed is to an object
100
Suggest an example of friction in everyday life
N/A
100
Forces are measured in Newtons
TRUE
200
Define gravity
A non-contact force that attracts objects to each other
200
List the 5 actions a force can make an object do
Accelerate
Decelerate
Stop
Change shape
Change direction
200
State the forces that act against gravity
Normal force
Air resistance
200
What happens to friction if a surface becomes rougher
The amount of friction increases
200
The following forces are balanced
TRUE
300
Define friction
a force created by two surfaces rubbing against each other
300
Which would be an example of an unbalanced force?
A. A plate sitting on a dining table
B. A ball at the top of a hill that is not moving
C. Earth orbiting the Sun
D. A baseball that has been thrown to home plate.
300
If you were to go to the moon, how would you feel?
A. Weightless
B. Heavy
C. Huge
D. Tiny
300
What kind of energy is created when friction increases?
Heat
300
An object can be moving even if the forces on it are balanced
FALSE
400
Define non contact force
a force that acts on an object without physical contact, operating across a distance
400
Why does a book on a table not move?
The force of gravity is pushing down, the normal force of the table is pushing up. The forces are balanced.
400
Is there more gravitational force between you and the Earth or an elephant and the Earth? and Why?
Elephant - more mass
400
What is the name given to another force that is a kind of friction between the air and other materials?
Air resistance
400
Air resistance is a non - contact force
FALSE
500
Define normal force
he support force exerted by a surface on an object in contact with it
500
What is the net force?
4000 N left
500
Explain why planets in our solar system do not 'escape into space'
The planet's are pulled towards the Sun by a gravitational force. The force is not strong enough to pull the planets into the sun. But, it is strong enough to keep them from escaping into deep space.
500
Explain why friction is both helpful (give at least two examples) and harmful (give at least two examples).
N/A
500
When two equal forces act in opposite directions, the net force is always 0
TRUE