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Weight = mass x gravity (9.8 m/s
2
) Units: kg
.
m/s
2
or Newtons (N)
Work = Force x distance W = F x d Units: Joules (J)
Rearranged: Force = Work ÷ distance Units: Newtons
distance = Work ÷ Force Units: meters
Power = Work ÷ time P = W ÷ t Units: J/s or Watts (W)
Rearranged: Work = Power x time Units: Joules (J)
time = Work ÷ Power Units: seconds (s)
Mechanical Advantage = Output Force ÷ Input Force (Resistance Force ÷ Effort Force)
or
Mechanical Advantage = Input Distance ÷ Output Distance (Effort Distance ÷ Resistance Distance)
Gravitational Potential Energy = mass x gravity (9.8 m/s
2
) x height GPE = m x g x h Units:
Joules
Rearranged: m = GPE ÷ (g
.
h) h = GPE ÷ (m
.
g)
Kinetic Energy = ½ mass x (velocity)
2
KE = .5 mv
2
Units: Joules
Rearranged: m = 2KE ÷ v
2
v =
Efficiency of a Machine = (Useful Work Output ÷ Work Input) x 100
Temperature Conversions
Celsius-Fahrenheit Conversion:
Fahrenheit temperature = (1.8 x Celsius temperature) + 32.0
0
F = 1.8 (C) + 32
0
Celsius temperature = (Fahrenheit temperature – 32) ÷ 1.8 C = (F – 32) ÷ 1.8
Celsius-Kelvin Conversion:
Kelvin = Celsius + 273 Celsius = Kelvin -273