What is a force?
A push or pull
What UNIT is used to measure the size of a force?
Newtons, N
What INSTRUMENT can be used to measure the size of a force?
A Newtonmeter
How can we show forces on a diagram?
With Arrows
What do arrows show on a diagram?
The direction of a force
What does the length of an arrow show on a diagram?
The longer the arrow, the bigger the force
Applied Force
The force where a person pushes of pulls and object
Weight/Gravity
The force that pulls objects towards earth
Thrust
The force produced by engines
Friction
The force when solid surfaces rub against each other.
Air resistance
The force when an object moves through the air
Water resistance
The force when an object moves through the water
Upthrust
The force that stops objects sinking in water
Lift
The force the stops airplanes from falling down towards earth
Normal contact force
The force that stops objects falling though solid surfaces
Interaction
When two objects act on each other with a force
How many forces are produced during one interaction?
Two
Contact Force
Forces that only happen when objects touch
Non-contact forces
Forces that can happen even when the objects are not touching
Name two non-contact forces
Weight, magnetism
Name the eight contact forces
Friction, thrust, air resistance, water resistance, lift, normal contact, applied force, upthrust
How can we squash an object?
Push on opposite sides of the object
Compression
The change in size when an object is stretched
How can we stretch an object?
Pull on opposite sides of the object
