Equations

Question 1

Weight

Answer 1

Weight (N) = mass (kg) x gravitational field strength (N/Kg)

W = m g

Question 2

Spring constant

Answer 2

Force applied to a spring (N) = spring constant (N/m) x extension (m)

F = k e

Question 3

Acceleration

Answer 3

Acceleration (m/s squared) = Change in velocity (m/s) / time taken (s)

a = Δv / t

Question 4

Momentum

Answer 4

Momentum Kg m/s = Mass (Kg) x Velocity (m/s)

p = m v

Question 5

Gravitational potential energy

Answer 5

GPE = Mass (Kg) x GFS (N/Kg) x Height (M)
Ep = m g h

Question 6

Power (Link potential difference and current)

Answer 6

Power (W) = Potential difference (V) x Current (A)

P = V I

Question 7

Power (Link work done and time)

Answer 7

Power (W) = Work done / Time (S)

P = W / t

Question 8

Power (Link energy transferred and time)

Answer 8

Power (W) = Energy transferred (J) / Time (s)

P = E / t

Question 9

Efficiency

Answer 9

Efficiency = useful output x total output

Question 10

Charge flow

Answer 10

Charge flow (Coulombs C) = Current (A) x time (s)
Q = I t

Question 11

Energy Transferred (Link power and time)

Answer 11

Energy transferred (J) = power (W) x time (s)
E = P t

Question 12

Density

Answer 12

Density (Kg/M cubed) = mass (kg) / volume (m cubed)

p = m / v

Question 13

Work done (Link force and distance along the line of action of the force)

Answer 13

Work done (Nm) = Force (N) x distance (m) (along the line of action of a force)
W = F s

Question 14

Distance travelled

Answer 14

Distance (m) = speed (m/s) x time (s)

s = v t

Question 15

Resultant force (Link mass and acceleration)

Answer 15

Resultant force (N) = mass (kg) x acceleration (m/s squared)
F = m a

Question 16

Kinetic energy

Answer 16

Kinetic energy (J) = 0.5 x mass (k/g) x (speed) squared
Ek = 0.5 m v(squared)

Question 17

Efficiency (link useful output energy transfer and useful input energy transfer)

Answer 17

Efficiency = Useful output energy transfer / Useful input energy transfer

Question 18

Wave speed

Answer 18

Wave speed = Frequency x wavelength

v = f λ

Question 19

Potential difference (Link current and resistance)

Answer 19

Potential difference (V) = Current (A) x Resistance (Ω)
V = I R

Question 20

Power (Link current and resistance)

Answer 20

Power (W) = current squared (A) x resistance (Ω)

Question 21

Energy transferred (link charge flow and potential difference)

Answer 21

Energy transferred (J) = Charge flow (Coulombs C) x Potential difference (V)