Physics equations

Question 1

Forces and motion - (distance, velocity and time)

Answer 1

speed or velocity (m/s) = distance (m) over time (s)

v=s/t

Question 2

Forces and motion - acceleration

Answer 2

acceleration (m/s^2) = difference in velocity/time (s)

a = (v-u)/t

Question 3

Forces and motion - force, mass and acceleration

Answer 3

force (N) = mass (kg) x acceleration (m/s^2)

f = ma

Question 4

Forces and motion - weight

Answer 4

weight (N) = mass (kg) x gravitational field strength (10N)

w=mg

Question 5

Forces and motion - momentum

Answer 5

momentum (kgm/s) = mass (kg) x velocity (m/s)

P = mv

Question 6

Forces and motion - force, change in momentum

Answer 6

force (N) = change in momentum (kgm/s) /time(s)

f = (mv-mu)/t

Question 7

Forces and motion - stop/think/break distance

Answer 7

Stopping distance = thinking distance + braking distance

Question 8

Forces and motion - moments

Answer 8

Clockwise moment = anti clockwise moment

Question 9

Electricity - resistance, voltage, current

Answer 9

Voltage (voltz) = current (amps) x resistance (ohms)

V = IR

Question 10

Electricity - charge, current, time

Answer 10

Charge (Coloumbs) = current (Amps) x time (seconds)

Q = IT

Question 11

Electricity - charge, voltage, energy transferred

Answer 11

Energy transferred (J) = charge (coulombs) x voltage (voltz)
E = QxV
^can be substituted with resistance and equation V = IR
Energy transferred = charge x current x resistance
E = Q x I x R

Question 12

Electricity - electrical power, current, voltage

Answer 12

Electrical power (Watts)  = current(amps) x voltage(voltz)
P = IV

Question 13

Electricity - energy transferred, current, voltage, time

Answer 13

Energy transferred (J) = current (amps)  x voltage (Voltz) x time (s)
E = IVt

Question 14

Waves - speed, frequency wavelength

Answer 14

Speed (m/s) = frequency (Hz) x wavelength (m)

v=fλ

Question 15

Waves - frequency, time

Answer 15

frequency (hertz) = 1/time (s)

Question 16

Waves, angles of incidence and reflection

Answer 16

angle of incidence = angle of reflection ( in a reflection )

Question 17

Waves - refractive index

Answer 17

refractive index = speed of light in vaccum/speed of light in the material
n=c/v

Question 18

Waves - critical angles

Answer 18

sin(critical angle) = 1/reflective index

sin C = 1/n

Question 19

Energy - efficiency

Answer 19

efficiency = useful enrgy output/total energy output x 100

Question 20

Energy - work done

Answer 20

work done(J) = force(N) x distance(m)
W= Fd

Question 21

Energy - power, work done, time

Answer 21

Power(Watts) = work done(J)/time taken(s)

P=w/t

Question 22

Energy - kinetic enrgy

Answer 22

KE = 1/2mass (kg) x velociy^2 (m/s)
KE = 1/2mv^2

Question 23

Energy - gravitational potential enrgy

Answer 23

GPE = mass (kg) x grativational field strength (10N) x height (m)
GPE = mgh

Question 24

Energy - GPE and KE

Answer 24

GPE = KE
mgh = 1/2mv^2

Question 25

Solids liquids and gases - density

Answer 25

Density(kg/m^3) = mass (kg)/volume (m^3)
ρ = m/V

Question 26

Solids liquids and gases - pressure

Answer 26

Pressure = force (N) / area (m^2)
p = F/A

Question 27

SLG - Pressure in depths

Answer 27

Pressure difference = height (m) x density (kg/m^3) x gravitational field strength (10N)
p = h x ρ x g

Question 28

SLG - temperature and pressure

Answer 28

Pressure1 / Temp.1 = constant = Pressure 2 / Temp. 2

P1 / T1 = P2 / T2

Question 29

SLG - pressure and volume

Answer 29

Pressure1 x Volume 1 = constant = Pressure 2 x Volume 2

P1V1 = P2V2

Question 30

SLG - specific heat capacity

Answer 30

Specific heat capacity = change in thermal energy/mass x change in temperature