Density Formula
Density = mass/volume
Speed formula
speed = distance/time
Acceleration formula
acceleration = final velocity-initial velocity/time
Force formula
Force = mass x acceleration
Momentum formula
momentum = mass x velocity
Impulse formula
impulse = force x time = change in momentum
Weight formula
Weight = mass x gravitational field strength
Moment of a force (formula)
moment of force about a point = Force x perpendicular distance from point
Hooke's Law formula
spring load = spring constant x spring extension (F=kx)
Pressure formula
pressure = force/area
Pressure in a liquid (formula)
pressure = density x g x depth
Temperature formula (kelvin to celsius)
Kelvin temperature = temperature in degrees celsius + 273
Compressing gases formula
pressure 1 x volume 1 = pressure 2 x volume 2 (boyles law)
Work formula
work = force x distance moved in the direction of force
gravitational potential energy formula
GPE= mass x gravity x height
kinetic energy formula
KE=1/2mv^2
Energy and temperature change (formula)
Energy transferred = mass x specific heat capacity x temperature change
Power formula
power = work/time or energy transferred/time
Efficiency formula
Useful energy output / total energy input (can be power/power or work/energy)
Waves formula
speed = frequency x wavelength
Refraction of light (formula)
refractive index = sine of angle of incidence/sine of angle of refraction
Total internal reflection (formula)
sine of critical angle = 1/refractive index
Current formula
current = charge / time
Potential difference formula
p.d. = work done/charge
Resistance formula
resistance= p.d./current
Resistors in series (formula)
R total equals R1 + R2 + R3 ....
Resistors in parallel (formula)
1/R = 1/R1 + 1/R2
Electrical energy formula
energy transferred=powerxtime (p.d. x current x time)
Transformers (formula)
output voltage/input voltage = output turns/input turns
For 100% efficient transformer (formula)
power input = power output
Electrical Power formula
power = p.d. x current = current^2 x resistance
Average orbital speed
orbital speed= 2π x average radius of orbit/orbital period
Hubble constant
the ratio of the speed at which the galaxy is moving away from the earth, H0=v/d
Refractive index
refractive index= speed of light in a vacuum/speed of light in medium
Period (in waves)
period = 1/frequency