Physics
What is the definition of a force?
A force is a push or pull of one body to another
What are forces measured in?
Newtons (N)
Name the types of forces
Thrust
Electrostatic
Air Resistance
Water Resistance
Upthrust
Friction
Weight
Reaction
Define thrust
Forward push on an object
Define electrostatic
Charges move between objects and are attracted to opposite charges
Define air resistance
Stopping force when an object is travelling through air
Define water resistance
Stopping force when an object is travelling through water
Define upthrust
Opposion to weight on a liquid
Define friction
Stopping force between two solid objects that opposes motion
Define weight
Pull on a mass by gravity
Define reaction
Occurs as opposition to weight on a solid
What is a contact force?
When objects are touching
What is a non-contact force?
A force that acts upon an object with no physical contact between them
What is a balanced force?
When the two forces acting upon an object are equal in size
What is an unbalanced force?
When one force acting upon an object is greater in size than the other
What is the equation for weight from mass?
weight = mass x gravitational strength field
What are four common magnetic materials?
Iron
Steel
Nickel
Cobalt
What is a soft magnetic material?
One which is easy to magnetise and demagnetise (iron)
What is a hard magnetic material?
One which is difficult to magnetise and demagnetise (steel)
What is the law of magnets?
Like poles repel
Opposite poles attract
Unmagnetised magnetic materials are always attracted to magnets
What is a magnetic field?
The area around a magnet where magnetic materials feel a force
What pole do magnetic fields always point to?
South
If you want two materials to attract, what type of charge do they need to have?
Opposite
What is the law of electrostatics?
Bodies with like charges repel
Bodies with opposite charges attract
Charges bodies and neutral bodies attract
Why does your hair stand on end at a Van de Graff generator?
Negative charges flow from the dome into the person
Every hair gains a negative charge
They will all try to repel each other
Why should you stand on an insulating platform?
If you weren't, the charges would disappear into the earth
What happens to your hair when you step off the platform?
The negative charges disappear into the earth and your hair drops back down
Why would someone get a bad shock if they touched you when you are on the platform?
The negative charges would use them as the closest parh down to the earth