Physics equations Flashcards
Forces and motion - (distance, velocity and time)
speed or velocity (m/s) = distance (m) over time (s)
v=s/t
Forces and motion - acceleration
acceleration (m/s^2) = difference in velocity/time (s)
a = (v-u)/t
Forces and motion - force, mass and acceleration
force (N) = mass (kg) x acceleration (m/s^2)
f = ma
Forces and motion - weight
weight (N) = mass (kg) x gravitational field strength (10N)
w=mg
Forces and motion - momentum
momentum (kgm/s) = mass (kg) x velocity (m/s)
P = mv
Forces and motion - force, change in momentum
force (N) = change in momentum (kgm/s) /time(s)
f = (mv-mu)/t
Forces and motion - stop/think/break distance
Stopping distance = thinking distance + braking distance
Forces and motion - moments
Clockwise moment = anti clockwise moment
Electricity - resistance, voltage, current
Voltage (voltz) = current (amps) x resistance (ohms)
V = IR
Electricity - charge, current, time
Charge (Coloumbs) = current (Amps) x time (seconds)
Q = IT
Electricity - charge, voltage, energy transferred
Energy transferred (J) = charge (coulombs) x voltage (voltz) E = QxV ^can be substituted with resistance and equation V = IR Energy transferred = charge x current x resistance E = Q x I x R
Electricity - electrical power, current, voltage
Electrical power (Watts) = current(amps) x voltage(voltz) P = IV
Electricity - energy transferred, current, voltage, time
Energy transferred (J) = current (amps) x voltage (Voltz) x time (s) E = IVt
Waves - speed, frequency wavelength
Speed (m/s) = frequency (Hz) x wavelength (m)
v=fλ
Waves - frequency, time
frequency (hertz) = 1/time (s)
Waves, angles of incidence and reflection
angle of incidence = angle of reflection ( in a reflection )
Waves - refractive index
refractive index = speed of light in vaccum/speed of light in the material
n=c/v
Waves - critical angles
sin(critical angle) = 1/reflective index
sin C = 1/n
Energy - efficiency
efficiency = useful enrgy output/total energy output x 100
Energy - work done
work done(J) = force(N) x distance(m) W= Fd
Energy - power, work done, time
Power(Watts) = work done(J)/time taken(s)
P=w/t
Energy - kinetic enrgy
KE = 1/2mass (kg) x velociy^2 (m/s) KE = 1/2mv^2
Energy - gravitational potential enrgy
GPE = mass (kg) x grativational field strength (10N) x height (m) GPE = mgh
Energy - GPE and KE
GPE = KE mgh = 1/2mv^2
Solids liquids and gases - density
Density(kg/m^3) = mass (kg)/volume (m^3) ρ = m/V
Solids liquids and gases - pressure
Pressure = force (N) / area (m^2) p = F/A
SLG - Pressure in depths
Pressure difference = height (m) x density (kg/m^3) x gravitational field strength (10N)
p = h x ρ x g
SLG - temperature and pressure
Pressure1 / Temp.1 = constant = Pressure 2 / Temp. 2
P1 / T1 = P2 / T2
SLG - pressure and volume
Pressure1 x Volume 1 = constant = Pressure 2 x Volume 2
P1V1 = P2V2
SLG - specific heat capacity
Specific heat capacity = change in thermal energy/mass x change in temperature