Forces p. 90 - 101 Flashcards
(28 cards)
What is a force?
A push or a pull
What makes an object stop moving?
A change in direction, or if it hits something.
Friction?
When two surfaces rub over each other.
Gravity?
Force of attraction that objects have on one another, because of their masses.
What did Sir Izaac Newton say?
“Every object in a state of motion tends to stay in that state of motion unless an external force is applied to it.”
What happens when forces is applied on an object?
Make it move Make it stop moving Change direction of movement Change shape Cancel out another force
What is a contact force?
Force acting between two objects that are touching each other
Exert?
To apply
Normal force?
Force exerted on object in contact with another stable object
Applied force?
Force applied to something: pushing lid down.
Frictional force?
Forces between two surfaces rubbing past each other
Tension force?
Force applied to cable tied at two ends, tension force pulls equally in both directions.
Spring force?
Created by a compressed or stretched spring
Air resistance force?
Resists movement of object through the air. Most obvious at highest speeds.
Non - contact force?
A force that acts over a distance
Magnetism?
The force that two magnets exert on each other.
Why does the earth remain in its orbit?
The gravitational pull of the sun, and the acceleration of the Earth, are the two forces that cancel each other out, and if the Sun gravitational pull was not opposed by another force, Earth would slam into it.
Chemical balance?
Measure masses smaller than 5kg accurately
Analytical balance?
Extremely sensitive.
Protected by a shield from air draughts and dust, which can influence the reading.
Can weigh masses accurately to the nearest 0,0001g
Mass?
Quantity of matter in an object
Matter?
Substance that occupies space and has mass
Balance?
Scale to measure mass
Weight?
Gravitational pull of the Earth on an object.
Spring balance?
Equipment which is used to measure small forces.
