Scalar quantities only have a magnitude and no direction. (speed, distance, mass, temperature, time)
Vector quantities have a magnitude and a direction. (force, velocity, displacement, acceleration,
momentum) Vectors are usually represented by an arrow-the length of the arrow shows the
magnitude, and the direction shows the direction of the quantity.
A force is a push or a pull on an object that is caused by it interacting with something.
When two objects have to be touching for a force to act, that force is called contact force.
(friction, air resistance, tension)
If the object do not need to be touching for the force to act, the force is a non-contact force.
(magnetic force, gravitational force, electrostatic force)
When two objects interact, there is a force produced on both objects. An interaction pair is a pair of
forces that are equal and opposite and act on two interacting objects. (Basically Newton’s 3 rd Law)
Gravitational force is the force of attraction between masses. This has two important effects:
On the surface of a planet, it makes all things fall towards the ground
It gives everything a weight
Mass is the amount of substance that is present in an object. It is going to be the same regardless of
where you are in the world. Mass is measured using a mass balance.
Weight is the force acting on an object due to gravity. Weight of the object changes with its location
as it depend on the strength of the gravitational mass. The lower the gravitational strength, the
lower the weight. Gravitational strength on Earth is 9.8N/kg. It is measure using a newtonmeter.
The centre of mass is defined as ‘the point at which an object’s mass is centred on’.
Mass and weight are directly proportional. W= m x g
Weight (N) = Mass (Kg) x Gravitational Field Strength (N/kg)
Learn about Free Body Diagrams
A resultant force is the overall force on a point or object. When a resultant force moves an object
through a distance, energy is transferred and work is done on the object.
One joule of work is done when a force of one newton causes an object to move a distance of a
metre. Conversion: 1J=1Nm; W=Fs
Work done (J) = Force (N) x Distance (m)
If all of the forces acting on an object combine to give you a resultant force of zero, the object is
equilibrium.
Elasticity is when a force acts on an object, the object may change shape by bending, stretching, or
compressing. A change in shape is known as deformation:
Elastic deformation is reversed when the force is removed
Inelastic deformation is not fully reversed when the force is removed- there is a permanent
change is shape
Springs can either be used in tension (spring is stretched) or compression (spring is squashed). They
have a store of elastic potential energy when they have changed shape.
Vector quantities have a magnitude and a direction. (force, velocity, displacement, acceleration,
momentum) Vectors are usually represented by an arrow-the length of the arrow shows the
magnitude, and the direction shows the direction of the quantity.
A force is a push or a pull on an object that is caused by it interacting with something.
When two objects have to be touching for a force to act, that force is called contact force.
(friction, air resistance, tension)
If the object do not need to be touching for the force to act, the force is a non-contact force.
(magnetic force, gravitational force, electrostatic force)
When two objects interact, there is a force produced on both objects. An interaction pair is a pair of
forces that are equal and opposite and act on two interacting objects. (Basically Newton’s 3 rd Law)
Gravitational force is the force of attraction between masses. This has two important effects:
On the surface of a planet, it makes all things fall towards the ground
It gives everything a weight
Mass is the amount of substance that is present in an object. It is going to be the same regardless of
where you are in the world. Mass is measured using a mass balance.
Weight is the force acting on an object due to gravity. Weight of the object changes with its location
as it depend on the strength of the gravitational mass. The lower the gravitational strength, the
lower the weight. Gravitational strength on Earth is 9.8N/kg. It is measure using a newtonmeter.
The centre of mass is defined as ‘the point at which an object’s mass is centred on’.
Mass and weight are directly proportional. W= m x g
Weight (N) = Mass (Kg) x Gravitational Field Strength (N/kg)
Learn about Free Body Diagrams
A resultant force is the overall force on a point or object. When a resultant force moves an object
through a distance, energy is transferred and work is done on the object.
One joule of work is done when a force of one newton causes an object to move a distance of a
metre. Conversion: 1J=1Nm; W=Fs
Work done (J) = Force (N) x Distance (m)
If all of the forces acting on an object combine to give you a resultant force of zero, the object is
equilibrium.
Elasticity is when a force acts on an object, the object may change shape by bending, stretching, or
compressing. A change in shape is known as deformation:
Elastic deformation is reversed when the force is removed
Inelastic deformation is not fully reversed when the force is removed- there is a permanent
change is shape
Springs can either be used in tension (spring is stretched) or compression (spring is squashed). They
have a store of elastic potential energy when they have changed shape.
