P3d: Work and power Flashcards
Equation for weight
weight = mass * gravitational field strength(on earth it is 10N/kg)
Work equation
work done (J) = force (N) * distance moved in direction of force (m)
Power equations(2)
power (W) = work done (J) / time (s)
power (W) = force (N) * speed (m/s)
What happens when work is done?
energy is transferred
What is power
a measurement of how quickly work is being done in Watts (W)
Implications of high fuel consumption (2)
more expensive as more fuel cost
more damaging to environment as more fossil fuels is burned and more pollution is released
Relationship between engine size and fuel consumption
more powerful an engine means it transfers more energy from its fuel per second, so increased fuel consumption
Why do vehicles have different power ratings?
heavier vehicles (lorries) have to do more work to move its mass up hills, or to work against friction
Why do cars have different engine sizes?
to supply more powe
