Formulae

Question 1

Kinetic Energy

Answer 1

Kinetic Energy = ½ x Mass x Speed²

KE = ½mv²

Question 2

Gravitational Potential Energy

Answer 2

GPE = Mass x Gravitational Field Strength x Height

GPE = mgh

Question 3

Power - two ways (not electricity)

Answer 3

Power = Energy Transferred / Time

P = E/t

AND

Power = Work Done / Time

P = W/t

Question 4

Efficiency (two ways)

Answer 4

Efficiency = Useful output energy transfer / Total input energy transfer

AND

Efficiency = Useful power output / Total power input

Question 5

Charge

Answer 5

Charge = Current x Time

Q = It

Question 6

Potential Difference

Answer 6

Potential Difference = Current x Resistance

V = IR

Question 7

Power - two ways (electrical)

Answer 7

Power = Potential Difference x Current

P = VI

AND

Power = Current² x Resistance

P = I²R

Question 8

(Electrical) Energy Transferred (two ways)

Answer 8

Energy Transferred = Power x Time

E = Pt

AND

Energy Transferred = Charge x Potential Difference

E = QV

Question 9

Density

Answer 9

Density = Mass/Volume

Question 10

Triple only

Pressure and volume in a gas

Answer 10

pressure x volume = constant

PV = constant

P₁V₁ = P₂V₂

Question 11

Weight

Answer 11

weight = mass × gravitational field strength

W = mg

Question 12

Work done

Answer 12

work done = force × distance

W = Fd

Question 13

Force on a spring

Answer 13

force = spring constant × extension

F = ke

Question 14

Moment of a force

Answer 14

moment of a force = force × distance

M = Fd

Question 15

Pressure

Answer 15

pressure = force/area

P = F/A

Question 16

Speed

Answer 16

speed = distance/time

or

distance = speed x time

Question 17

Acceleration

Answer 17

Acceleration = change in speed/time

a = ch in s/t

Question 18

Force and acceleration

Answer 18

resultant force = mass × acceleration

F = ma

Question 19

Momentum

Answer 19

momentum = mass × velocity

p = mv

Question 20

Wave speed

Answer 20

wave speed = frequency × wavelength