force
anything that causes an object to accelerate
unit of force
newtons, N
force arrows
size of arrow is directly proportional to magnitude of force applied
formula for force
mass (kg) x acceleration (m/s2)
weight
force of gravity on an object
formula for weight
mass (kg) x 10
hookes law
the extension of a spring is directly proportional to he force applied
friction
a force which opposes motion between two objects in contact