Test Flashcards
What is a force?
A push, pull, twist or turn (or a mix of several) that causes a change in speed, shape and (or) direction.
What is friction?
Friction is a force between two surfaces, causing them to heat up and wear.
What is weight measured in?
NEWTONS!! (not grams)
What is gravity?
The force that holds you down to Earth.
What is drag?
The force acting against anything moving in the Earth’s atmosphere.
What is lift ?
The force pushing upwards on an object flying in the air.
What is upthrust?
The force pushing upwards on an object in liquid.
What is thrust?
A push caused by an engine.
What is mass measured in?
Grams (kilo)
What is the formula to work out speed?
s=d/t
What is the formula to work out distance?
d=ts
What is the formula to work out time?
t=d/s
Who discovered the law of elascticity
Robert Hooke
When forces are balanced the force arrows are…
Equal
Weight is…
mass multiplied by the gravitational field strength.
Hooke’s law show’s that …
The greater the force on an elastic object, the greater the extension.
Why is friction useful?
It can help us too decelerate.
Why is friction a menace?
It lowers our rate of acceleration.
When is friction used?
Car breaks.
When is drag used?
Parachuting.
The gravitational force can affect your…
Weight.
But not change your…
Mass
When you are moving at a constant speed the…
Force arrows will all be equal
When accelerating the…
Force arrow pointing the way you are going will be longer than the rest.
When decelerating the…
Force arrow pointing opposite the way you wish to go will be larger than the rest.
Why is gravity important?
Without it we would be flying.
An engine makes which force occur?
Thrust
A parachuter uses which force
Air resistance.
Two surfaces rubbing against each other makes…
Friction
Forces are
Nescesary
