Forces
When an object lies on a surface, the surface exerts an equal and opposite force.
Normal / reactive force
Two forces equal in size and opposite in direction.
Balanced forces
The amount of matter or material present in an object
Mass
Friction is this type of force
Contact force
A simple machine made of a long, rigid object such as a stick or a metal rod
Lever
When an object is immersed in a fluid, wholly or partially, the fluid exerts an upward force opposite its weight.
Buoyancy / buoyant force
A stationary object stays at rest, the forces are
Balanced
The name given to the pulling force of gravity on an object
Weight
Friction always acts
In a direction opposite to motion
The pivot point of a lever
Fulcrum
A force that acts over a distance
Non-contact force
A moving object continues to move at the same speed and in the same direction the forces are
Balanced
The force of gravity is influenced by which factors
This substance reduces friction by creating a thin, separating film between surfaces
Lubricant
A wheelbarrow is this class of lever
Second class
The forces that opposes movement of an object through a fluid such as air or water
Drag force / drag resistance
You can tell that a force is unbalanced if there is a change in
Speed, direction or shape
The amount of gravity in space, in Newtons
0N
This type of energy is produced as an undesired effect of friction
Heat energy
A double inclined plane that moves through another object
Wedge
The force of attraction or repulsion between two charged particles.
Electrostatic force
When there is a net force (non-zero resultant force) the forces are
Unbalanced
When the force of air resistance acting on an object matches the force of its weight as it falls.
Terminal velocity
The method of friction reduction utilised by a hovercraft
Stopping the contact of moving parts
In this type of simple machine, you use a smaller force over a longer distance
Inclined plane