21 Equations Flashcards
What equation do we use to calculate weight?
weight (N) = mass (kg) x gravitational field strength (N/kg)
W = m g
What equation do we use to calculate work done?
work done (J) = force (N) x distance W = F s
What equation do we use to calculate force applied to a spring?
force applied to a spring (N) = spring constant (N/m) x extension (m)
F = k e
What equation do we use to calculate distance travelled?
distance travelled = speed x time
s = v t
What equation do we use to calculate acceleration?
acceleration = change in velocity / time taken a = Δv / t
What equation do we use to calculate resultant force?
resultant force = mass x acceleration
F = m a
What equation do we use to calculate momentum?
momentum = mass x velocity p = m v
What equation do we use to calculate kinetic energy?
……………………………………………………………2
kinetic energy = 0.5 x mass x (speed)
…………………2
Ek = 1/2m v
What equation do we use to calculate gravitational potential energy?
gravitational potential energy = mass x gravitational field strength (g) x height
Ep = m g h
What equation links to power, energy transferred and time?
power = energy transferred / time P = E / t
What equation links to power, work done and time?
power = work done / time P = W / t
What two equations do we use to calculate efficiency?
efficiency = useful output energy transfer / total input energy transfer efficiency = useful power output / total power input
What equation do we use to calculate wave speed?
wave speed = frequency x wavelength
v = f λ
What equation do we use to calculate charge flow?
charge flow = current x time
Q = I t
What equation do we use to calculate potential difference?
potential difference = current x resistance
V = I R
