Formulae Flashcards
What are the rules for current, voltage and resistance in series and parallel circuits?
What is the equation for centripetal force in terms of linear velocity?
F = mv2/r
What does the graph of acceleration of an object in SHM look like?
In antiphase with displacement (π phase difference)
What is the equation of the force exerted on a mass due to another mass?
F = -GMm/r2
- M is the mass of the point mass exerting the force
- m is the mass of the point mass the force is being exerted upon
- G is the gravitational constant (6.67x10-11 Nm2kg-2 )
- r is the distance between the two centres of the point masses
What is the equation for Power in terms of voltage and resistance?
P = V2/R
What is the equation for energy in terms of charge and voltage?
E = QV
What is the equation for Power in terms of energy and time?
P = E/t
What is the equation for centripetal acceleration in terms of angular velocity?
a = ω2r
What is the equation for the energy of a photon?
(Photoelectric Effect)
E = hf = hc/λ
What is the equation for centripetal force in terms of angular velocity?
F = mω2r
How do you break down a weight of a object on a slope into components?
What does the graph of velocity of an object in SHM look like?
π/2 out of phase with displacement
What is the equation for the time period of an oscillating spring in SHM?
T = 2π√m/k
- T is time period
- m is mass
- k is spring/stiffness constant
What is the equation relating turns of wire of a transformer and voltage?
Vs/Vp = Ns/Np
- Vs is the voltage at the secondary coil
- Vp is the voltage at the primary coil
- Ns is the number of turns at the secondary coil
- Np is the number of turns at the primary coil
What is the equation describing the photoelectric effect?
hf = work function + KEmax
What is the equation for Resistivity of a wire?
p = R x A/L
Resistivity = Resistance x area/length
What is the equation for resistance in terms of voltage and current?
R = V/I
What is the equation for acceleration of an object in SHM?
a = -ω2x
where x is displacement
What is the equation for wavespeed in terms of frequency and wavelength?
v = fλ
What is the equation for a potential divider?
VOut = VIn x R1/R1+R2
What is the equation for the maximum acceleration of an object in SHM?
amax = ω2A
where A is maximum displacement
How are frequency and time period related?
f = 1/T
What is Snell’s law?
n1sinϴ1 = n2sinϴ2
What is the equation for the veloicty of a body in a circular orbit of a body?
v = √GM/r
- m is the mass of the object being orbited
- r is the distance from the centre of the body being orbited to the satellite
What is the equation for wavespeed in terms of distance and time?
wavespeed = distance/time
What is the equation relating linear velocity and angular velocity?
v = rω
What is the equation for current in terms of charge and time?
I = Q/t
What is the equation relating distance and power?
Power = 1/distance2
implying: Power1 x (Distance1)2= Power2 x (Distance2)2
What is the equation for the time period of a pendulum oscillating in SHM?
T = 2π√L/g
- T is time period
- L is length of pendulum
- g is gravitational field strength
What is the equation for electron drift velocity?
I =nAve
- n is the number of electrons per unit volume
- A is the area of the wire
- v is the mean drift velocty
- e is the charge of an electron
What is the equation for gravitational field strength?
g = F/m
What is the equation for a materials refractive index in terms of speed of light and velocity of light in the material?
n = c/v
where n is the refractive index
What is the equation for angular velocity in terms of time period?
ω = 2π/T
What is the equation for the critical angle?
SinC = 1/n
What is the equation for the max velocity of an object in SHM?
hint: when velocity is max, x = 0
vmax = ωA
What is the equation for Power in terms of current and voltage?
P = IV
What is the equation relating the currents and voltages at the primary and secondary coils of a transformer?
HInt: P = IV
IpVp = IsVs
What is the equation for the speed of an electron accelerated through a potential difference?
eV = 1/2mv2
What is the conservation of energy?
mgh = ½mv2
gravational energy lost/gained = kinetic energy gained/lost
What are the equations for internal resistance?
Emf = V + Ir
Emf = I(R + r)
where r is internal resistance
What is the eqaution for centripetal acceleration in terms of linear velocity?
a = v2/r
What is the equation for the displacement of an object in SHM when timing began at the midpoint?
x = Asin(ωt)
where A is maximum displacement
What is the equation for the gravitational field strength in a radial field?
g = -GM/r2
- G is gravitational constant (6.67 x10-11 Nm2kg-2 )
- M is the mass of the body causing the radial field
- r is the radius of the body
What does the graph of displacement of an object in SHM look like?
Cosine graph
What is the equation for angular velocity in terms of frequency?
ω = 2πf
What is the formula for intergration by parts?
∫ v ⋅ du/dx = uv - ∫ dv/dx ⋅ u
where v and du/dx are the two parts of the integral
What is the equation to work out the coeffiecient of restitution?
Hint: helps with momentum problems
e = speed of separation/speed of approach
e = (vb-va)/(ua-ub)
where e is the constant of restitution ranging between 1 (perfectly elastic collision) and 0 (perfectly inelastic collision)
What is Kepler’s third law?
T2∝r3
What equation related the time period of an orbit to its radius?
T2 = (4π2/GM)r3
What is the equation for the velocity of an object in SHM?
v = ±ω√A2-x2
where A is maximum displacement
What is the eqaution defining angular motion?
ω = ϴ/t
What is the equation for the displacement of an object in SHM when timing began at the maximum?
x = Acos(ωt)
where A is max displacement
What is the equation for Power in terms of current and resistance?
P = I2R
