1. average speed = distance / time
v = d/t
(m / s)
(m)
(s)
2. acceleration = change in velocity / time taken for change
a=v–u/t
(m / s2)
3.
Force
(m / s)
=
(s)
mass X acceleration
F = ma
(metre/second squared, m/s²)
(newton, N) (kilogram, kg)
4. Weight
=
mass X gravitational field strength
W = mg
(newton, N)
5. momentum
(kilogram ,kg)
(newton/kilogram, N/kg)
= mass X velocity
p = mv
(kg m/s)
(kg)
(m/s)
6. Force = change in momentum / time
F = (mv - mu) / t
(N)
(kg m/s)
(s)
8.
moment = Force X perpendicular distance between force and pivot,
moment = Fd
(Nm)
(N)
(m)
9. Sum of clockwise moments = Sum of anticlockwise moments (for equilibrium
or balanced)
.........................................................................................................................................................
.................
10. Work done = Force X distance moved in direction of force
W=Fxd
(joule, J)
(newton, N)
(metre, m)
11. Power = work done / time taken
P=W/t
(Watt, W)
(J)
(s)
12. change in gravitational potential energy = weight X change in vertical height,
GPE = mgh
(joule, J)
(newton, N)
(metre, m)
13. kinetic energy = ½
X mass X velocity²
KE = ½ mv²
(joule, J)
(m/s)²
(kilogram, kg)
14. efficiency = useful energy transferred / total energy supplied,
ɛ = useful energy / total energy
(no unit)
(J)
(J)
15. Total energy before event = Total energy after event (conservation of
energy)
......................................................................................................................................................
....................
16.
charge
=
current
X
time
Q = It
(coulomb, C)
17.
Voltage
(ampere, A)
=
current
X
(second, s)
resistance
V = IR
(volt, V)
18.
Power
(ampere, A)
= voltage
X
(ohm, Ω)
current
P = VI
(watt, W)
(volt, V
(ampere, A)
19. electrical energy = voltage X current X time
E=ItV
(J)
(V)
20. voltage across secondary coil
voltage across primary coil
(A)
=
(s)
Number of turns on secondary coil ,
Number of turns on primary coil
Vs = Ns
Vp
Np
21. Secondary coil output power = Primary coil input power
Vs Is =
V p Ip
.........................................................................................................................................................
.................
22. wave velocity = frequency X
wavelength
v=fλ
( m/s)
23.
(hertz, Hz)
frequency = 1 / time period
f =1/T
(Hz)
(s)
(metre, m)
24. Refractive index = sine of angle of incidence / sine of angle of refraction,
n = sin i / sin r
25. sine of critical angle = 1 / refractive index
sin c = 1 / n
.......................................................................................................................................................
...................
26. Density = mass / volume
ρ = m /V
(kg/m3)
(kg)
(m3)
27. Pressure = Force / Area
p = F/A
(Pa)
(N)
(m2)
28. Pressure in a liquid = liquid density X height of liquid X gravity
p = ρ h g
(Pa)
(kg / m2)
(m)
(m / s2)
29. Boyle's Law: first pressure X first volume = second pressure X second
volume,
p 1 V1 = p 2 V2
(Pa)
(m3)
(m3)
(Pa)
30. Pressure Law: first pressure / first Kelvin temperature = second pressure /
second Kelvin temperature,
p1 / T 1 = p2 / T 2
(Pa)
(K)
(Pa)
(K)
.......................................................................................................................................................
...................
31. change in thermal energy = mass × specific heat capacity × change in
temperature
ΔQ = m × c × Δθ
(J)
(kg)
( J/kg C)
(C)
32. thermal energy for a change of state = mass × specific latent heat
Q=m×L
(J)
(kg)
( J/kg)