Equations

Question 1

what is work done?

Answer 1

doing work transfers energy from one store to another by applying a force to move an object

Question 2

what is power?

Answer 2

the rate of energy transfer

1 Joule of energy = 1 watt of power

Question 3

what is specific heat capacity?

Answer 3

the energy needed to raise 1kg of a substance by 1°C

Question 4

equation for work done

Answer 4

Work done = force x distance

W = Fs

Question 5

what is the equation for power?

Answer 5

power = energy transferred / time
P = E/t
power = work done / time
P = W/t

Question 6

what is the equation linking SHC and energy?

Answer 6

change in thermal energy = mass x SHC x temperature change

J = kg x J/kg x °C

Question 7

what is the equation for efficiency?

Answer 7

useful power output / total power output

useful output energy transfer / total input energy transfer

Question 8

what is the equation for kinetic energy?

Answer 8

½ x mass x (speed)^2

0.5 x kg x m/s

Question 9

what is the equation for gravitational potential energy?

Answer 9

mass x gravitational field strength x height

kg x N/kg x metres

Question 10

what is the equation for elastic potential energy?

Answer 10

½ x spring constant x (extension)^2

0.5 x N/m x m