vector quantity
magnitude and direction
vector quantity examples (5)
- force
- velocity
- displacement
- acceleration
- momentum
scalar quantity
magnitude
no direction
scalar quantity examples
- speed
- distance
- time
- temperature
- mass
force
a push or pull on an object caused by an interaction
3 non contact forces
- magnetic
- gravitational
- electrostatic
what is gravitational force
force of attraction between masses
mass is directly proportional to
weight
what is drag
resistance in a fluid
eg. air resistance
resultant force
single, overall force acting on an object that represents the vector sum of all individual forces combined
what happens if a resultant force moves an object
work is done
how does an object achieve equilibrium
forces are balanced
if all forces on an object combine to give a resultant force of 0, the object is in equilibrium
elastically deformed meaning
object can go back to it’s original shape when force is removed
inelastically deformed meaning
object does not return to it’s original shape and length after force is removed
extension is directly proportional to
force
stiffer spring =
greater spring constant
force and extension practical
- measure length of natural spring
- add a mass to spring (allow to rest) record mass and measure new length
(extension is the change in length) - repeat until at least 6 measurements
acceleration
rate of change of velocity
uniform acceleration
constant acceleration
terminal velocity
maximum speed achieved by an object free falling through a gas or liquid
inertia
tendency for motion to remain unchanged
mass and force affect acceleration
practical
- place peice of card on trolley with gap (to interrupt signal on light gate twice)
- connect trolley to peice of string holding masses below end of table
- record time displayed by light gate and masses increased by
stopping distance =
thinking distance + braking distance
what is thinking distance affected by
- speed
- reaction time
