energy Flashcards
How many joules are in one kilojoule
1000J
Where do humans get their energy from?
Food
Name the three forms of potential (stored) energy.
Gravitational, elastic and chemical
What is kinetic energy?
Moving
Write out the law of conservation of energy.
Energy cannot be created or destroyed it can only be changed from one form to another
What is a transducer?
A device that converts energy from one form to another
Write out the equation for percentage efficiency.
Percentage efficiency = useful energy output /total energy input x 100
Calculate the percentage efficiency. A light bulb uses 400J of electrical energy and converts 250J into light energy and 150J into heat energy.
250 /400 x 100 = 62.5%