Physics Unit 9: Force and Motion
Friction
A force that opposes motion between two surfaces that are in contact
The unit of force
Newton
Friction produces what?
heat
The gravitational force on Earth is
10N/kg i.e. every 1Kg has 10N force acting on it
Gravity
A force of attraction between objects that is due to their masses.
Weight
A measure of the force of gravity on an object
___________________________ of the object doesnt change
Mass
The unit of weight is
Newton
Force meter
Piece of equipment containing a spring that is used to measure forces
Force Arrows
Show the direction of a force
Air resistance is less when the shape is
Streamlined
Air resistance
The force that opposes the motion of objects that move through the air
________________________ of an object changes and it depend upon the gravtional force
Weight
What is the weight of a man on the moon if his mass is 60Kg on Earth?(Note: gravity of Moon is 1.6N/kg)
Weight=massx gravity Weight = 60x1.6=96N
What is the weight of a man on the Earth is his mass is 60kg on the Earth? ( Note: the gravity of Earth =
Weight=massx gravity Weight= 60x10=600N
Force
a push or pull on an object; measured in Newtons (N)
The unit of mass
kilogram
Friction causes
objects to slow down and stop
Mass
the amount of matter in an object
Weight formula
w=mg Weight = Mass x Gravity