Word Equations

Question 1

W = m g

Answer 1

Weight = mass x gravitational field strength

Question 2

W = F s

Answer 2

Work done = force x distance

Question 3

F = k e

Answer 3

Force applied to a spring = spring constant x entension

Question 4

M = F d

Answer 4

Moment of a force = force x distance

Question 5

P = F/A

Answer 5

Pressure = force normal to a surface / area of that surface

Question 6

s = v t

Answer 6

Distance travelled = speed x time

Question 7

a = △ v / t

Answer 7

Acceleration = change in velocity / time taken

Question 8

F = m a

Answer 8

Resultant force = mass x acceleration

Question 9

p = m v

Answer 9

Momentum = mass x velocity

Question 10

E ₖ = 1/2 m v^2

Answer 10

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

Question 11

E ₚ = m g h

Answer 11

Gravitational potential energy = mass x gravitational field strength x height

Question 12

P = E / t

Answer 12

Power = energy transferred / time

Question 13

P = W / t

Answer 13

Power = work done / time

Question 14

Efficiency (1) = (energy transfer)

Answer 14

Efficiency = useful output energy transfer / total input energy transfer

Question 15

Efficiency (2) = (power input)

Answer 15

Efficiency = useful power output / total power input

Question 16

v = F λ

Answer 16

Wave speed = frequency x wavelength

Question 17

Q = I t

Answer 17

Charge flow = current x time

Question 18

V = I R

Answer 18

Potential difference = current x resistance

Question 19

P = V I

Answer 19

Power = potential difference x current

Question 20

P = I^2 R

Answer 20

Power = (current)^2 x resistance

Question 21

E = P t

Answer 21

Energy transferred = power x time

Question 22

E = Q V

Answer 22

Energy transferred = charge flow x potential difference

Question 23

P = m / V

Answer 23

Density = mass / volume

Question 24

p = h p g

Answer 24

Pressure due to a column of liquid = height of column x density of liquid x gravitational field strength (g)

Question 25

v^2 - u^2 = 2 a s

Answer 25

(Final velocity)^2 - (initial velocity)^2 = 2 x acceleration x distance

Question 26

F = m △ v / △ t

Answer 26

Force = change in momentum / time taken

Question 27

E ₑ = 1/2 k e^2

Answer 27

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

Question 28

△ E = m c △ 0

Answer 28

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

Question 29

Period = ?

Answer 29

Period = 1 / frequency

Question 30

Magnification = ?

Answer 30

Magnification = image height / object height

Question 31

F = B I l

Answer 31

Force on a conductor (at right angles to a magnetic field) carrying a current = magnetic flux density x current x length

Question 32

E = m L

Answer 32

Thermal energy for a change of state = mass x specific latent heat

Question 33

Vₚ / Vₛ = Nₚ / Nₛ

Answer 33

Potential difference across primary coil / Potential difference across secondary oil = Number of turns in primary coil / Number of turns in secondary coil

Question 34

Vₛ Iₛ = Vₚ Iₚ

Answer 34

Potential difference across primary coil x current in primary coil = Potential difference across secondary coil x Current in secondary coil

Question 35

p V = constant

Answer 35

(For gases) pressure x volume = constant