Unit 1 - Forces and Motion Flashcards
define acceleration
the rate of change of velocity
in a distance time graph what is the gradient
speed
in a speed time graph what is the gradient
acceleration
in a speed time graph what is the area under the graph
distance
state the factors affecting the braking distance
- “initial” speed
- road condition
- tyre condition
- brakes condition
- friction between tyre and floor
- slope of the road
what is meant by a scalar quantity
a quantity that has magnitude only
ex speed
what is meant by a vector quantity
a quantity that has magnitude and direction
ex velocity
what is meant by terminal velocity
when an object is falling in air , terminal velocity is constant velocity when air resistance balances weight
——- is a force that opposes motion
friction
state the formulae to find (resultant) force
resultant force= mass x acceleration
Rf = m x a
factors affecting the thinking distance
- how tired or sleepy the driver was
- age of the driver
- alcohol or drugs consumption
- dstractiion of the driver
the acceleration changes even though the driving force does not change
suggest two possible reasons for this change in acceleration
- the air resistance increase so acceleration decreased
- the surface being driven on changes so it has a higher friction resulting in a lower acceleration
define center of mass or gravity
the point where weight acts
state the principle of moment
total anticlockwise moment is equal to anticlockwise moment in equilibrium
state the principle of momentum
total momentum before collision is equal to total momentum after collision in a closed system
