Equations Flashcards
Weight
Weight (N) = mass (kg) x gravitational field strength (N/Kg)
W = m g
Spring constant
Force applied to a spring (N) = spring constant (N/m) x extension (m)
F = k e
Acceleration
Acceleration (m/s squared) = Change in velocity (m/s) / time taken (s)
a = Δv / t
Momentum
Momentum Kg m/s = Mass (Kg) x Velocity (m/s)
p = m v
Gravitational potential energy
GPE = Mass (Kg) x GFS (N/Kg) x Height (M) Ep = m g h
Power (Link potential difference and current)
Power (W) = Potential difference (V) x Current (A)
P = V I
Power (Link work done and time)
Power (W) = Work done / Time (S)
P = W / t
Power (Link energy transferred and time)
Power (W) = Energy transferred (J) / Time (s)
P = E / t
Efficiency
Efficiency = useful output x total output
Charge flow
Charge flow (Coulombs C) = Current (A) x time (s) Q = I t
Energy Transferred (Link power and time)
Energy transferred (J) = power (W) x time (s) E = P t
Density
Density (Kg/M cubed) = mass (kg) / volume (m cubed)
p = m / v
Work done (Link force and distance along the line of action of the force)
Work done (Nm) = Force (N) x distance (m) (along the line of action of a force) W = F s
Distance travelled
Distance (m) = speed (m/s) x time (s)
s = v t
Resultant force (Link mass and acceleration)
Resultant force (N) = mass (kg) x acceleration (m/s squared) F = m a
Kinetic energy
Kinetic energy (J) = 0.5 x mass (k/g) x (speed) squared Ek = 0.5 m v(squared)
Efficiency (link useful output energy transfer and useful input energy transfer)
Efficiency = Useful output energy transfer / Useful input energy transfer
Wave speed
Wave speed = Frequency x wavelength
v = f λ
Potential difference (Link current and resistance)
Potential difference (V) = Current (A) x Resistance (Ω) V = I R
Power (Link current and resistance)
Power (W) = current squared (A) x resistance (Ω)
Energy transferred (link charge flow and potential difference)
Energy transferred (J) = Charge flow (Coulombs C) x Potential difference (V)
