Name the 9 types of energy
Heat (thermal), light, sound, kinetic, strain (elastic), electrical, nuclear, chemical, gravitational potential
What is the law of conservation of energy?
Energy can not be destroyed, only transferred from one form to another.
Calculate the efficiency of a light bulb that transfers 40J of electrical energy into 8 joules of light energy
0.2 or 20%
What are the units of efficiency?
It doesn’t have any
How many joules of energy does a 15 W radio transfer every second?
15 J
How many units of electricity would a 1200W kettle transfer in 5 hours?
5 x 1.2 = 6kWh or 6 units