energy on the move Flashcards
what does the kinetic energy of an object depend on?
its mass and speed
what are the main fuels for cars?
petrol and diesel oils
what does the use of fossil fuels cause?
more pollution, especially in cities
cost more to run
decrease supplies of non-renewable fossil fuels
name a type of bio fuel?
organic waste
what are the 2 types of electric cars?
battery driven
solar powered-fitted with solar panels
what are the units of KE?
joules
what are fuel consumption data based on?
ideal road conditions and a car being driven at a steady speed
how are values obtained?
in urban and non-urban conditions
what is the problems with fossil fuelled power stations?
they pollute the local atmosphere and cause acid rain
why can it be argued that battery operated cars pollute the atmosphere?
they require electricity from fossil fuelled power stations
if fossil fuels run out what will we have to rely on?
bio-fuelled electricity
solar-powered vehicles
electric vehicles recharged using electricity from nuclear power stations or renewable sources
what happens when the car stops?
its kinetic energy changes into heat in the brakes, tyres and road
what does work done by brakes equal?
loss in kinetic energy
what is the equation for change in kinetic energy?
braking force x braking distance
what happens if the speed of a car doubles?
the kinetic energy quadruples
the braking distance quadruples
what are petrol and diesel made from?
oil
which is more refined petrol or diesel oil?
petrol
what happens in the engine of a petrol engine car?
fuel is ignited by a spark from a spark plug
what happens in the engine of a diesel engine car?
it is ignited by hot compressed air in a cylinder
why is a diesel engine more efficient than a petrol engine?
diesel cars have lower co2 emissions than petrol cars. But diesel engines produce more of the emissions that affect air quality and can damage our health such as NO and particulates.
how can friction forces on moving objects such as vehicles be reduced?
by streamlining their shapes by:
shaping car roof boxes
making high speed cars wedge like in shape
angling lorry deflectors
what are factors affecting the fuel consumption of a car?
amount of energy required to increase its kinetic energy
that amount of energy required for it to do work against friction
its speed
how it is driven, such as excessive acceleration and deceleration, constant braking and speed changes
road conditions, such as a rough surface
what are the disadvantages of electric powered cars?
battery takes up a lot of room
limited range before recharging
expensive to buy but cost of recharging is low
solar powered cars rely on the sun shining and need backup batteries
