Equations for acceleration
a = (v-u) / t
acceleration = change in velocity / time taken
Equation for force
- F = m x a
Weight
W = m x g
weight = mass x gravitational field strength
Efficiency
Efficiency = (useful energy transferred by device) / (total energy supplied to the device)
Momentum
p = m x v
momentum = mass x velocity
Wave speed (2)
- v = f x lambda
- wavespeed = frequency x wavelength
- v = x / t
- wavespeed = distance over time
Density
- p = m / V
- density = mass / volume
Work done
E = F x d
- work done = force x distance moved in direction of force
Change in gravitational potential energy
delta GPE = m x g x change in height
Kinetic energy
KE= 1/2 x m x v^2
1/2 x mass x speed^2
Power
P = E / t power = work done / time taken
Electrical power (2)
- P = I x V
- current x potential different
- P = I^2 x R
- current^2 x resistance
Force exerted on a spring
- F = k x x
- force exerted on a spring = spring constant x extension
Current
- I = Q / t
Current = charge(coulomb) / time
Voltage
- V = E / Q
voltage = energy transferred / charge - V = I x R
voltage = current x resistance (ohms)
Energy transferred (electrical)
E = ItV energy = current x time x voltage
Velocity
v = s /t velocity = distance / time
Work done
W = mg
- mass x gravitational field strength
Energy transferred
E = F x d
Pressure
P = F / A
Alpha Decay
- Mass number: -4
- Atomic number: -2
- 4, 2 alpha particle, helium
Beta decay
- Mass number: same
- Atomic: +1
- 0, -1 beta particle
Speed of light
c = f x lambda
- frequency x wavelength
Efficiency
useful energy out / total energy in
