Equations

Question 1

Constant motion

Answer 1

D = st

Question 2

Acceleration with velocity and time

Answer 2

A = v-u/t

Question 3

Weight and mass

Answer 3

W = mg

Question 4

Density - kg/m^3

Answer 4

ρ = m/v

Question 5

Force with acceleration

Answer 5

F = ma

Question 6

Terminal velocity

Answer 6

W = air resistance

Question 7

Hooke’s law

Answer 7

F = kx
K = spring constant/N/m
X = extension/m

Question 8

Moment of a force- Nm

Answer 8

τ = Fd

F = perpendicular force

Question 9

Principle of moments

Answer 9

F1 x d1 = f2 x d2

Total clockwise moments = total anti-clockwise moments

Question 10

Mechanical work done - change in energy/J

Answer 10

ΔE = fd

Question 11

Kinetic energy

Answer 11

1/2 x m x v^2

Question 12

GPE/J

Answer 12

E = mgh

Question 13

Power with work done

Answer 13

P = ΔE/t

Question 14

Pressure with area/Pa

Answer 14

P = F/A

Question 15

Pressure due to liquid

Answer 15

p = ρgh

Question 16

Boyles law- pressure and volume relationship

Answer 16

pV = constant
p1 x V1 = p2 x V2

Question 17

Specific heat capacity/J/kg degrees c

Answer 17

c = E/mΔt

Question 18

Thermal capacity/ J/degrees c

Answer 18

thermal capacity = m x c
Thermal capacity = E/Δt

Q = total heat

Question 19

Specific latent heat/J/kg

Answer 19

L = E/m

E = total energy
M = mass change

Question 20

Current with charge

Answer 20

I = Q/t

Question 21

Ohms law

Answer 21

V = IR
V directly property to I

R = resistance/ohms(Ω)

Question 22

Voltage with charge

Answer 22

V = E/Q

E = energy
Q = charge/coulombs

Question 23

Current in series

Answer 23

The same everywhere

Question 24

Voltage in series

Answer 24

V1 = V2+V3

V1 = emf

Question 25

Power with voltage and current

Answer 25

P = IV

Question 26

Power with resistance and voltage

Answer 26

P = v^2/R

Question 27

Power with current and resistance

Answer 27

P = I^2 x R

Question 28

Energy with power and time

Answer 28

E = pt
E = IVT

Question 29

Momentum

Answer 29

P = mv

P = momentum
Mv = mass x volume

Question 30

Force with change in impulse

Answer 30

F =Δp/t

P = momentum

Question 31

impulse(change of momentum) / kgm/s

Answer 31

ΔP = FΔt

Question 32

impulse(change of momentum) / kgm/s

Answer 32

ΔP = FΔt

Question 33

Conservation of momentum

Answer 33

M1xV1 = M2xV2

Total momentum - add when going same direction
- minus when opposite direction

Question 34

Wave speed with wavelength

Answer 34

V = fλ
f = frequency
λ= wavelength

Question 35

Frequency with time

Answer 35

F = 1/t

Question 36

Refractive index with speeds of light

Answer 36

n = c/v

c = speed of light (vacuum)
v = speed of light (medium measured)

Question 37

Refractive index with critical angle

Answer 37

n = 1/c angle

Question 38

Refractive index with angle of incidence

Answer 38

n = sin(i)/sin(r)

i is always the bigger angle

Question 39

Left hand rule

Answer 39

Motor effect

Thumb - force
First finger - field
Second finger - current

Question 40

Right hand rule

Answer 40

Generator effect

Question 41

Power in a transformer

Answer 41

IV = IV

Question 42

Voltage and turns in a transformer

Answer 42

Vp/Vs = Np/Ns

Question 43

Impulse with mass

Answer 43

M(v-u)

Question 44

Orbital Speed

Answer 44

o.s. = 2π r/T