Physics Equations

Question 1

Equation relating weight, mass and gravity

Answer 1

W = mg
Weight = mass x gravity
Newtons = kilograms x newtons per kilogram

Question 2

Equation relating density, mass and volume

Answer 2

p = m / V
Density = mass / volume
Kilograms per metre³ = kilograms / metres³

Question 3

Equation relating load, spring constant and extension

Answer 3

F = kx
Load = spring constant x extension
Newtons = newtons per metre x metres

Question 4

Equation relating resultant force, mass and acceleration

Answer 4

F = ma
Resultant force = mass x acceleration
Newtons = kilograms x metres per second²

Question 5

Equation relating pressure, force and area

Answer 5

p = F / A
Pressure = force / area
Newtons per metre² = newtons / metres²

Question 6

Equation relating work, force, distance and change in energy

Answer 6

W = Fd = ΔE
Work = force x distance = change in energy
Joules = newtons x metres = joules

Question 7

Equation relating kinetic energy, mass and velocity

Answer 7

KE = 1/2 x m x v²
Kinetic energy = half x mass x velocity²
Joules = 1/2 x kilograms x (metres per second)²

Question 8

Equation relating gravitational potential energy, mass, gravity and height

Answer 8

GPE = mgh
Gravitational potential energy = mass x gravity x height
Joules = kilograms x newtons per kilogram x metres

Question 9

Equation relating power, change in energy and time

Answer 9

P = ΔE / t
Power = change in energy / time
Watts = joules / seconds

Question 10

Equation relating efficiency, useful energy output and energy input

Answer 10

Efficiency = useful energy output / energy input x 100%

Question 11

Equation relating efficiency, useful power output and power input

Answer 11

Efficiency = useful power output / power input x 100%

Question 12

Equation relating speed of wave, frequency and wavelength

Answer 12

v = f λ
Speed of wave = frequency x wavelength
Metres per second = Hertz x metres

Question 13

Equation relating refractive index, angle of incidence ‘i’ and angle of refraction ‘r’

Answer 13

n = sin(i) / sin(r)
Refractive index = sin(angle of incidence) / sin(angle or refraction)

Question 14

Equation relating current, charge and time

Answer 14

I = Q / t
Current = charge / time
Amperes = coulombs / seconds

Question 15

Equation relating resistance, potential difference and current

Answer 15

R = V / I
Resistance = voltage / current
Ohms = volts / amperes

Question 16

Equation relating power, current and potential difference

Answer 16

P = IV
Power = current x potential difference
Watts = amperes x volts

Question 17

Equation relating energy, current, potential difference and time

Answer 17

E = IVt
Energy = current x potential difference x time
Joules = amperes x volts x seconds

Question 18

Equation relating potential difference to the number of coils on each side of the transformer

Answer 18

(Vₚ / Vₛ) = (Nₚ / Nₛ)

Question 19

Equation relating current and potential difference between the two sides of a transformer

Answer 19

IₚVₚ = IₛVₛ

Question 20

Equation relating resistivity, resistance, length and area

Answer 20

P = (R x a)/l
Resistivity = (Resistance x Area) / length

Question 21

Describe the relationship between resistance, length and area

Answer 21

Resistance ∝ length
Resistance ∝ 1/area
Resistance ∝ length/area