Equations

Question 1

What’s the equation for weight?

Answer 1

weight = mass × gravitational field strength (g)

Question 2

What’s the equation for work done?

Answer 2

work done = force × distance (along the line of action of the force)

Question 3

What’s the equation for finding force applied to a spring?

Answer 3

force applied to a spring = spring constant × extension

Question 4

What’s the equation for moment of a force?

Answer 4

moment of a force = force × distance (normal to direction of force)

Question 5

What’s the equation for pressure?

Answer 5

pressure = force normal to a surface / area if that surface

Question 6

What’s the equation for distance travelled?

Answer 6

distance travelled = speed × time

Question 7

What’s the equation for acceleration?

Answer 7

acceleration = change in velocity / time taken

Question 8

What’s the equation for resultant force?

Answer 8

resultant force = mass × acceleration

Question 9

What’s the equation for momentum?

Answer 9

momentum = mass × velocity

Question 10

What’s the equation for kinetic energy?

Answer 10

kinetic energy = 0.5 × mass × (speed)2

Question 11

What’s the equation for gravitational potential energy?

Answer 11

gravitational potential energy = mass × gravitational field strength (g) × height

Question 12

What’s the equation for power? (energy transfer one)

Answer 12

power = energy transferred / time

Question 13

What’s the equation for power? (work done one)

Answer 13

power = work done / time

Question 14

What’s the equation for efficiency? (energy transfers one)

Answer 14

efficiency = useful output energy transfer / total input energy transfer

Question 15

What’s the equation for efficiency? (power one)

Answer 15

efficiency = useful power output / total power input

Question 16

What’s the equation for wave speed?

Answer 16

wave speed = frequency × wavelength

Question 17

What’s the equation for charge flow?

Answer 17

charge flow = current × time

Question 18

What’s the equation for potential difference? (resistance)

Answer 18

potential difference = current × resistance

Question 19

What’s the equation for power? (potential difference)

Answer 19

power = potential difference × current

Question 20

What’s the equation for power? (resistance)

Answer 20

power = (current)2 × resistance

Question 21

What’s the equation for energy transferred? (power)

Answer 21

energy transferred = power × time

Question 22

What’s the equation for energy transferred? (charge flow)

Answer 22

energy transferred = charge flow × potential difference

Question 23

What’s the equation for density?

Answer 23

density = mass / volume