Forces and motion Flashcards
What is a force
The means that causes a mass to change it’s momentum
Name seven types of forces
Air resistance, water resistance, magnetism, gravity, friction, pressure, weight
How are forces measured and in which unit of measurement
Newton meter and they are measured in newtons
What five things can forces make objects do
Speed up, slow down, change direction, turn, change shape
What do balanced forces produce
No change in movement
What do unbalanced forces produce
A change in movement
Name a kind of frictional force
Air resistance
What does air resistance do
Slows an object down that is moving through the air
What does friction do
It try’s to stop objects sliding past each other
Give 4 good points of friction relating to riding a bike
Tyres gripping the road, brakes rubbing on the rim of the wheel so you can stop, gripping the handle bars and the friction of the nuts and bolts to hold the bike together
Give 2 bad points of friction relating to riding a bike
Air resistance limits top speed and friction wastes energy
Describe 2 ways of reducing friction
Smoothen the surface and add a lubricant
Explain the difference between mass and weight
Mass is the amount of matter in an object, it will always stay the same anywhere. Weight is a type of force caused by the pull of gravity
Can an objects mass be different to its weight
Yes it can
What is the equation to calculate weight
Weight=mass x gravitational field strength
What is Stretching
Stretching is distortion which happens when a force acts on an object which cannot move or when several forces act in different directions
Give an example of a permanent stretch
Clay
Give an example of a temporary stretch
Elastic band
What is Hooke’s law of elasticity
The amount of stretch is directly proportional to the force acting on it
