Physics Equations

Question 1

Density

Answer 1

Density (kg/m3) = mass (kg) / volume (m3) -> p = m/V

Question 2

Force

Answer 2

Force (N) = mass (kg) x acceleration (m/s2) -> F =ma

Force (N) = springconstant (N/m) x extension (m) -> F = ke

Question 3

Moment

Answer 3

Moment (Nm) = force (N) x distance (m) -> Total clockwise moments = Total anticlockwise moments -> Moment = Fd

Question 4

Power

Answer 4

Power (W) = work Done (J) / time (s) -> P = Fd/t
Power (W) = energy transferred (J) / time (s) -> P = E/t
Power (W) = current (A) x voltage (V) -> P = IV
P = I(squared)R
P = V(squared)/R

Question 5

Pressure in Solids

Answer 5

Pressure in Solids (Pa) = force (N) / surface area (m2) -> p = Fa

Question 6

Weight

Answer 6

Weight (N) = mass (kg) x gravitational field strength (m/s2) -> w = mg

Question 7

Work Done

Answer 7

Work Done (J) = force (N) x distance (m) -> W = Fd
Work Done (J) = Energy Transferred

Question 8

Charge

Answer 8

Charge (C) = current (A) x time (s) -> Q = It

Question 9

Electrical Energy

Answer 9

Electrical Energy (J) = charge (C) x voltage (V) -> E = QV
Electrical Energy (J) = power (W) x time (s) -> E = Pt
E = VIt (Voltage x Current x Time)

Question 10

Voltage

Answer 10

Voltage (V) = current (A) x resistance (Ohms) -> V = IR

Question 11

Resistance

Answer 11

Resistance in Series -> R = R1 + R2 + R3 + …

Resistance in Parellel -> 1/R = 1/R1 + 1/R2 + …

Question 12

Transformer

Answer 12

Vp/Vs = Np/Ns
IpVp = IsVs

Question 13

Kinetic Energy

Answer 13

Kinetic Energy (J) = 1/2 x mass (kg) x velocity2 (m/s2) -> KE = 1/2m(v2)

Question 14

Gravitational Potential Energy

Answer 14

Potential Energy (J) = mass (kg) x gravity (N/kg) x height (m) -> PE = mgh

Question 15

Law of Conservation of Energy

Answer 15

Loss of Energy = Gain of Energy

Question 16

Period

Answer 16

Period (s) = 1 / frequency (Hz) -> T = 1/f

Question 17

Wave Speed

Answer 17

Wave Speed (m/s) = frequency (Hz) x wavelength (m) -> v = f x lambda

Question 18

Refractive Index

Answer 18

Refractive Index = sin (angle of incidence) / sin (angle of refraction)
-> n = sin i / sin r
Refractive Index = speed of light in air / speed of light in medium -> n = V air / V medium
Refractive Index = 1 / sin (critical angle) -> n = 1 / sin c