Forces
What is a force?
A force is a push or pull that is ecerted on an object.
What is effect?
An effect is what forces do.
(Sometimes a force cam be too small to observe a visible effect. e.g gravity.)
List four effects of a force.
1. Movement
2. Deformation
3. Change of direction
4. Rotation.
How does movement affect force?
A force can cause:
> a stationary object to start moving.
>a moving object to accelerate.
> a moving object to decelerate.
What is a newton?
The newton (N) is the unit in which force is measured.
100g = 1N
1 Kg = 10N
What is a newton meter?
A newton meter is used to measure force. It is a spring balance containing a metal spring.
(The newton meter is equipped with a scale marked or calibrated in newton.)
How do forces work?
Forces always work in pairs simultaneously on various objects and never occur as a single force.
What is a balanced force?
Forces are balanced when two forces acting in opposite directions are equal.
The nett force is 0N. (No nett force.)
What is an unbalanced force?
Forces are unbalanced when two forces acting in opposite directions are not equal.
The nett force is greater than 0N.
What does the effect of the various forces that act together depend on?
The effect of the various forces that act together depends on the amount and direction in which the force acts.
What is a nett force/ resultant force?
A nett force/resultant force is formed when two or more forces act on an object and combine.
It is the effect of all the forces acting on an object.
List the two types of forces.
~ Contact forces
~ Non - contact forces (field forces)
What is a contact force?
A contact force is exerted when two objects are in contact with one another.
List six examples of contact forces.
frictional force
tensile force
compression force
thrust force
tension force
air resistance
What is a non-contact force?
A non-contact force (field force) is exerted over a distance and is a force as a result of action at a distance between two objects.
List three examples of non-contact forces.
Gravitational force
Magnetic force
Electrostatic force