Kinetic energy, work and power Flashcards
What is the equation to work out work done?
work done = force (newton, n) x distance moved in the direction of the force (metres, m)
What is power the measure of?
Power is the measure of how quickly work is being done.
What is the equation to work out power?
power = work done divided by time taken
What is work done equal to?
Work done is equal to the energy transferred.
What is kinetic energy lost to when a car breaks?
When a car breaks, kinetic energy is lost to thermal energy.
What happens if the speed of the car doubles?
When the speed of the car doubles, the kinetic energy and braking distance quadruple.
What is power measured in?
Power is measured in watts.
What is kinetic energy?
Kinetic energy is energy of movement. All moving objects have kinetic energy.
What does the amount of gravitational kinetic energy an object on earth have depend on?
- its mass
- the height above ground
What is the equation to work out gravitational potential energy?
gravitational potential energy = mass (kg) x gravitational field strength x vertical height
What is the weight of an object?
The weight of an object is the size of the force of gravity pulling the object down.
What is the equation to work out weight?
weight = mass x gravitational field strength
What 2 things does kinetic energy depend on?
- speed
- mass
What is the equation for kinetic energy?
kinetic energy = 1/2 x mass x velocity
