Physics Equations

Question 1

Kinetic Energy?

Answer 1

E = ½mv²

Kinetic Energy = ½ x Mass(kg) x Speed²(m/s)²

Question 2

Gravitational Potential Energy?

Answer 2

E = mgh

Gravitational Potential Energy = Mass(kg) x Gravitational Field Strength(N/kg) x Height(m)

Question 3

Elastic Potential Energy?

Answer 3

E = ½ke²

Elastic potential energy = ½ x Spring Constant(N/m) x Extension(m)²

Question 4

Change in Thermal Energy?

Answer 4

ΔE = mcΔθ

Change in thermal energy = Mass(kg) x Specific Heat Capacity(J/kg°C) x Temperature Change(°C)

Question 5

Power?

Answer 5

P = E  ÷ t
Power (W) = Energy Transferred (J)  ÷ Time (s)
or 
P = W ÷ t
Power(W) = Work done(J)  ÷ Time(s)
or
P = VI
Power(W) = Potential difference(V) x Current(A)

Question 6

Efficiency?

Answer 6

Useful output energy transfer ÷ Total input energy transfer
or
Useful power output ÷ Total power input

Question 7

Charge?

Answer 7

Q = It
Charge(C) = Current(A) x Time(s)

Question 8

Potential difference?

Answer 8

V = IR
Potential difference(V) = Current(A) x Resistance(Ω)

Question 9

Energy transferred?

Answer 9

E = Pt
Energy transferred(J) = Power(W) x Time(s)
or 
E = QV
Energy transferred(J) = Charge flow(C) x Potential difference(V)

Question 10

Density?

Answer 10

p = m ÷ v
Density(kg/m3) = Mass(kg) ÷ Volume(m3)

Question 11

Energy?

Answer 11

E = m x L
Energy = Mass(m) x Specific Latent Heat(L)

Question 12

Constant?

Answer 12

Constant = pV
Constant = pressure(Pa) x Volume(m3)

Question 13

Weight?

Answer 13

W = m x g
Weight(N) = Mass(kg) x Gravitational Field Strength(N/kg)

Question 14

Work Done?

Answer 14

W = Fs
Work Done(J) = Force(N) x Distance(m)

Question 15

Force?

Answer 15

F = ke
Force(N) = Spring Constant(N/m) x Extension(m)
F = mΔv ÷ Δt
Force(N) = Change in momentum(kgm/s) ÷ change in time(s)

Question 16

Moment?

Answer 16

M = Fd
Moment(Nm) = Force(N) x Distance(m)

Question 17

Pressure?

Answer 17

p = F ÷ A
Pressure(Pa) = Force(N) ÷ Area(m²)
or 
p = hρg
Pressure(Pa) = Height(m) x Density(kg/m3) x Gravitational field strength (N/kg)

Question 18

Distance travelled?

Answer 18

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

Question 19

Acceleration?

Answer 19

a = Δv ÷ t
Acceleration(m/s²) = change in velocity(m/s) ÷ time(s)

Question 20

Final Velocity?

Answer 20

v² - u²= 2as
Final Velocity(m/s) - Initial velocity(m/s) = 2 x acceleration(m/s²) x distance(s)

Question 21

Resultant force?

Answer 21

F = ma
Resultant force(N) = Mass(kg) x Acceleration(m/s²)

Question 22

Stopping Distance?

Answer 22

Stopping Distance = Thinking Distance ÷ Braking Distance

Question 23

Momentum?

Answer 23

p = mv

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

Question 24

Period?

Answer 24

T = 1 ÷ f
Period(s) = 1 ÷ Frequency(Hz)

Question 25

Wave Speed?

Answer 25

v = fλ
Wave Speed(m/s) = Frequency(Hz) x Wavelength(m)