work and power Flashcards
what does the amount of work done depend on?
the size of the force acting on an object in newtons
distance the object is moved in metres
what is work done measured in?
joules
what is the equation for force?
force=mass x acceleration
what is weight due to?
gravitational attraction that acts towards the centre of the earth
when is work done?
when a force moves an object in the direction it acts
when does the amount of work done increase?
when the size of the force increases
when the distance moved in the direction of the force increases
what is kinetic energy transferred to when driving in a car?
transferred into heat by the brakes
what is the equation for kinetic energy loss?
=work done by brakes
what is power measured in?
watts
what is a large amount of power measured in?
kilowatts
what is the difference between many cars? and what are these 2 related to?
different power ratings
different engine sizes
related to fuel consumption
what are the main problems with cars?
burning fuels pollutes the environment
car exhaust gases are harmful and the production and transport of fuels create many hazards
how does carbon dioxide contribute to climate change?
it is a major source of greenhouse gases which contributes to climate change
what is the amount of vehicle excise duty paid based on?
carbon dioxide emissions
what is the equation for time taken?
work done divided by power
