Physics - Work and Energy Flashcards
What is work?
Work is done when a force acts on a moving body. Work is done whenever a force moves something.
What is the equation for work done?
Work Done = Force x Distance
How can an object posses energy?
position (potential energy)
motion (kinetic energy)
deformation (elastic energy)
What does the amount of GPE an object on Earth has depend on?
mass
height above the ground
How do you calculate GPE?
GPE(J) = mass(kg) x gravitational field strength (N/Kg) x change in height(m)
What does the KE of an object depend on?
mass
speed
What is kinetic energy?
Energy which an object possesses by being in motion.
What is elastic potential energy?
A force acting on an object may cause the shape of an object to change. Elastic objects can store elastic potential energy if they are stretched. For example, this happens when a catapult is used.
How do you calculate kinetic energy?
KE = 1/2mv^2
What is Hooke’s law?
When an elastic object, such as a spring, is stretched, the increased length is called its extension. The extension of an elastic object is directly proportional to the force applied to it
What is the equation for the force of an extension of an elastic object?
Force(N) = K-spring constant-(N/m) x X -extension-(m)
What is the elastic limit?
If a spring is stretched too much, for example, it will not return to its original length when the load is removed.
What factors can change the fuel consumption of vehicles?
driven uphill a lot
carrying large loads
driven at high speed
driven over rough road surfaces
driven with underinflated tyres
What are frictional losses in a car?
shape and size of the vehicle
friction between the car tyres
What is rolling resistance?
Rolling resistance is a measure of the force necessary to move the tyre forward and is directly proportional to the weight of the load supported by the tyre.
