P1 Using Energy Flashcards
1
Q
Name the 9 types of energy
A
Heat (thermal), light, sound, kinetic, strain (elastic), electrical, nuclear, chemical, gravitational potential
2
Q
What is the law of conservation of energy?
A
Energy can not be destroyed, only transferred from one form to another.
3
Q
Calculate the efficiency of a light bulb that transfers 40J of electrical energy into 8 joules of light energy
A
0.2 or 20%
4
Q
What are the units of efficiency?
A
It doesn’t have any
5
Q
How many joules of energy does a 15 W radio transfer every second?
A
15 J
6
Q
How many units of electricity would a 1200W kettle transfer in 5 hours?
A
5 x 1.2 = 6kWh or 6 units
