Mock equations

Question 1

relationship between speed, distance and time

Answer 1

average speed= distance moved / time taken

Question 2

equation for acceleration

Answer 2

acceleration= change in velocity / time taken

Question 3

equation for force

Answer 3

force = mass x acceleration

Question 4

equation for weight

Answer 4

weight = mass x gravitational field strength

Question 5

equation for moments

Answer 5

moment = force x perpendicular distance

Question 6

equation for power

Answer 6

power = current x voltage

Question 7

equation for voltage

Answer 7

voltage = current x resistance

Question 8

equation for charge

Answer 8

charge = current x time

Question 9

equation for energy transferred (with charge and voltage)

Answer 9

energy = charge x voltage
OR
energy= current x time x voltage

Question 10

equation for wave speed

Answer 10

wave speed = frequency x wavelength

Question 11

equation for frequency

Answer 11

frequency = 1 / time period

Question 12

equation for refractive index

Answer 12

refractive index = sin(angle of incidence) / sin(angle of refraction)

Question 13

relationship between critical angle and refractive index

Answer 13

sin(critical index) = 1/ refractive index

Question 14

equation for energy efficiency

Answer 14

efficiency = useful energy output/ total energy input x 100%

Question 15

equation for work done/energy transferred (with force and distance)

Answer 15

work done = force x distance moved

Question 16

equation for gravitational potential energy

Answer 16

GPE = mass x gravitational field strength x height

Question 17

equation for kinetic energy

Answer 17

kinetic energy = 1/2 x mass x speed2 (squared)

Question 18

equation for density

Answer 18

density = mass / volume

Question 19

equation for pressure

Answer 19

pressure = force / area

Question 20

equation for pressure difference

Answer 20

pressure difference = height x density x gravitational field strength

Question 21

equation for change in thermal energy

Answer 21

change in thermal energy = mass x specific heat capacity x change in temp

Question 22

relationship between pressure and kelvin temp (of a fixed mass of gas at constant volume)

Answer 22

P1 / T1 = P2 / T2
(T = temp)

Question 23

relationship between pressure and volume (of a fixed mass of gas at constant temp)

Answer 23

P1V1 = P2V2

Question 24

relationship between input and output voltages and No_ turns for a transformer

Answer 24

input (primary) voltage / output (secondary) voltage = primary turns / secondary turns

Question 25

relationship between input and output power in transformers (and condition for it to work)

Answer 25

input power = output power
primary voltage x primary current = secondary voltage x secondary current
for 100% efficiency

Question 26

orbital speed equation

Answer 26

orbital speed = (2 x Π x orbital radius) / time period

Question 27

equation relating wavelength, velocity of a galaxy and speed of light

Answer 27

change in wavelength / wavelength in reference galaxy = velocity of galaxy / speed of light