energy Flashcards
What is a system?
An object or group of objects.
When a ball hits a wall some kinetic energy is…
Transferred as sound.
What is energy measured in?
Joules.
What is the equation for kinetic energy?
1/2 x mass x speed squared.
What is elastic potential?
Energy stored in a spring when it is stretched.
What is the equation for elastic potential energy?
1/2 x spring constant x extension squared.
What is spring constant measured in?
Newtons per metre.
How do you calculate gravitational potential energy?
mass x gravitational field strength x height.
What is gravitational field strength measured in?
Newtons per kilogram.
What is power measured in?
Watts.
What 2 things is power the rate of?
Energy transferred and work done.
What are the 2 equations for power?
Energy transferred. Work done.
————————— or ——————-
Time. Time
Energy transfers cannot be…
Created or destroyed.
What 3 things can happen to energy transfers?
~They can be transferred usefully
~They can be stored
~They can be dissipated
What does lubrication do?
Reduces friction so less heat energy is lost.