Contact and Non-Contact Forces
Force is a vector quantity-vector quantities have a magnitude and a direction
Lots of physical quantities are vector quantities: force, velocity, displacement, acceleration, momentum,etc
Some physical quantities only have magnitude and no direction, these are called scalar quantities:speed, distance, mass, temperature, time, etc
Vectors are usually represented by an arrow-the length of the arrow shows the magnitude and the direction of the arrow shows the direction of the quantity
Velocity is a vector, but speed is a scalar quantity. Both bikes are travelling at the same speed, but they have different velocities because they are travelling in different directions
A force is a push or a pull on an object that is caused by it interacting with something
All forces are either contact or non-contact forces
When two objects have to be touching for a force to act, that force is called a contact force
If the objects do not need to be touching for the force to act, the force is a non-contact 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 Newtons third law)
The sun and the earth are attracted to each other by the gravitational force. This is a non-contact force. An equal but opposite force of attraction is felt by both the sun and earth.
A chair exerts a force on the ground, whilst the ground pushes back at the chair with the same force. Equal but opposite forces are felt by both the chair and the ground
Force is a vector quantity-vector quantities have a magnitude and a direction
Lots of physical quantities are vector quantities: force, velocity, displacement, acceleration, momentum,etc
Some physical quantities only have magnitude and no direction, these are called scalar quantities:speed, distance, mass, temperature, time, etc
Vectors are usually represented by an arrow-the length of the arrow shows the magnitude and the direction of the arrow shows the direction of the quantity
Velocity is a vector, but speed is a scalar quantity. Both bikes are travelling at the same speed, but they have different velocities because they are travelling in different directions
A force is a push or a pull on an object that is caused by it interacting with something
All forces are either contact or non-contact forces
When two objects have to be touching for a force to act, that force is called a contact force
If the objects do not need to be touching for the force to act, the force is a non-contact 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 Newtons third law)
The sun and the earth are attracted to each other by the gravitational force. This is a non-contact force. An equal but opposite force of attraction is felt by both the sun and earth.
A chair exerts a force on the ground, whilst the ground pushes back at the chair with the same force. Equal but opposite forces are felt by both the chair and the ground
