Equations

Question 1

Weight

Answer 1

Weight = mass x gravitational field strength

Question 2

Work done

Answer 2

Work done = force x distance ( along the line of action of the force)

Question 3

Force applied to a spring

Answer 3

Force applied to a spring = spring constant x extension

Question 4

Moment of a force

Answer 4

Moment of a force = force x distance (normal to direction of force)

Question 5

Pressure

Answer 5

Pressure = force normal to a surface | divided by | area of that surface

Question 6

Distance travelled

Answer 6

Distance travelled = speed x time

Question 7

Acceleration

Answer 7

Acceleration = change in velocity | divided by | time taken

Question 8

Resultant force

Answer 8

Resultant force = mass x acceleration

Question 9

Momentum

Answer 9

Momentum = mass x velocity

Question 10

Gravitational potential energy

Answer 10

Gravitational potential energy = mass x height x gravitational field strength

Question 11

Efficiency 1

Answer 11

Efficiency = useful output energy transfer | divided by | useful input energy transfer

Question 12

Efficiency 2

Answer 12

Efficiency = useful power output | divided by | total power output

Question 13

Energy transferred 1

Answer 13

Energy transferred = power x time

Question 14

Energy transferred 2

Answer 14

Energy transferred = Charge of flow x potential difference

Question 15

Density

Answer 15

Density = mass | divided by | volume

Question 16

Kinetic energy

Answer 16

Kinetic energy = 0.5 x mass x (speed)^2

Question 17

Elastic potential energy

Answer 17

Elastic potential energy = 0.5 x spring constant x (extension)^2

Question 18

Change in thermal energy

Answer 18

Change in thermal energy = mass x specific heat capacity x temperature change