Physics - Forces Flashcards
What is a Scalar quantity
Scalar quantities have magnitude (size) only
Define vector quantity
Vectors have both magnitude (size) and direction
What is a force?
A push or pull
When are forces contact?
When objects are touching
When are forces non-contact?
When objects are not touching
Give an example of a contact force
Friction, air resistance, tension and normal contact force
Given an example of a non-contact force
Gravitational force, electrostatic force and magnetic force
What is weight?
The force acting on an object due to gravity.
What is mass?
The amount of matter in an object.
What is the equation linking weight, mass and gravitational field strength?
Weight = mass x gravity
What is used to measure weight?
Newtonmeter
Where does the weight of any object act from?
Centre of mass
What is a resultant force?
A single force to represent multiple forces
How do you calculate a resultant force?
Take away (opposite directions) or add (same direction) the forces.
When is work done on an object?
When a force moves it a distance.
What is equation linking work done, force and distance?
Work done = force x distance
How many Joules is one Newton-metre?
1 joule
What happens to the temperature of an object when work is done against friction?
It increases
What happens to an elastic object up to the limit of proportionality?
Elastic deformation (It is able to return to its original length)
What happens to an elastic object after the limit of proportionality?
Inelastic deformation (It will not return to its original length)
What is the relationship between force and extension for an elastic object?
Directly proportional
What is equation linking force, the spring
constant and extension?
Force = spring constant x extension
Is distance a scalar or vector quantity?
Scalar
Is displacement a scalar or vector quantity?
Vector
Is speed a scalar or vector quantity?
Scalar
Is velocity a scalar or vector quantity?
Vector
What is displacement?
Both distance and Direction
What is the typical value of walking speed?
1.5 m/s
What is the typical value of running speed?
3 m/s