Topic 4 Flashcards
What is the thinking distance?
Distance the car travels in the time between the diver noticing the hazard and applying the breaks
What two things is thinking distance effected by
Your reaction time
How fast your going
What is breaking distance
Distance the car travels during its deceleration whilst the brakes are being applied
What four main factors effect braking distance
How fast your going
The mass of vehicle
How good your breaks are
How good the grip is(friction between tyres and road)
What three factors effect the grip
Road surface
Weather
Tyres
What tyre tread depth is essential for getting ride of water inw et conditions and what is it called
1.6mm
“Aquaplaning”
What kind of quantity is momentum
Vector quantity
-has size and direction
Momentum is always
Conserved when no other forces act
When forces act on an object it causes it to
Change momentum
What effects does a larger force have on momentum and acceleration
Faster change of momentum and greater acceleration
The longer it takes for the change in momentum
The smaller the force (car crash)
What three factors do cars have to increase the time taken for change in momentum
Crumble zones
Seat belts
Air bags
What do crumble zones do to increase the time taken for change in momentum
Crumble on impacts increasing time taken for car to stop
What do seat belts do do increas time taken for change in momentum
Stretch slightly, increasing time taken for wearer to stop
Reducing four e acting on chest
What do air bags do
Slow you down gradually
What happens when a force moves an object
Energy is transferred and work is done
When work is done it can be both
Useful
Wasted
Work is measured in (energy transferred)
Joules
Power is
The rate of doing work
Power is measured in
Watts or j/s
Anything that’s moving has
Kinetic energy
name two principles of conserving energy
Energy can never be created or destroyed-only transferred from one form to another
Energy is only useful when it’s transferred from one form to another
Give two examples of forms that energy is transferred by
Heat
Sound
Describe how heat energy dissipates to surroundings
Is transferred to cooler surroundings, which then become warmer. This causes the energy to become less concentrated- it dissipates
What does the principle of conservation of energy say about the total amount of energy when it dissipates
The amount of energy stays the same
Still there but can’t be easily used or gotten back again
What is the sum of the distance it takes to stop a car made up of
Thinking distance
Breaking distance
Kinetic energy gained=
Gravitational potential energy lost
When something falls gravitational potential energy is converted into
Kinetic energy
Further something falls the faster it goes
