Chapter 3 - Forces Flashcards
what is a force
a force is a push or a pull
the S.I unit of force
newton ( n )
what is a push
a push is a force when you exert an object further away from you ( eg. pushing a car )
what is a pull
a pull is a force when you exert an object closer to you
what are the 4 changes to the motion of an object when a force has occured
- make a stationary object move
- make a moving object stop
- make the moving object slower or faster
- change the direction of a moving object
when there are 2 or more forces act on an object, we can….
calculate its net force ( textbook page 44 )
if the net force is 0 we can say that ….
the object is balanced and there is no change in the motion
what is the S.I unit of length
Meter ( M )
How to convert cm to m
÷ 100
How to convert m to cm
× 100
How to convert m to km
÷ 1000
How to convert km to m
× 1000
What is the S.I unit of time
seconds ( s )
how long is 1 minute ( in seconds )
60 seconds
how long is 1 hour ( in minutes )
60 minutes
how long is 1 hour ( in seconds )
3600 seconds
what is speed
speed is the distance moved per minute
what is the S.I unit for speed
meters per second ( m/s ) or kilometer per hour ( km/h )
what is the formula for speed
distance ÷ time
what is the formula for time
distance ÷ speed
what is the formula for distance
speed × time
what is the formula for average speed
total distance ÷ total time
what happens if an object moves faster
it accelerates
what happens if an object moves slower
it deaccelerates
what is acceleration ?
it is the change of speed
what is the S.I unit for acceleration
m / s2
what is another unit for acceleration
km/h2
what is the formula for acceleration
final speed - initial speed ÷ time taken ( seconds )
when an object is at rest it will remain stationary unless…
a force acts onto it
if the force is applied in the same direction as the motion
the object will move faster
for example when we apply a force to push a door, it will turn its hinges this turning effect is called ….
the moment of force
the moment of force has 2 factors one of them is,
the size of force : the larger the force , larger the moment
the moment of force has 2 factors another one of them is
the perpendicular distance : larger the perpendicular distance, the larger the moment
