Physics - Equations Flashcards
Acceleration =
( final velocity - initial velocity ) divided by time
A= (v-u)/t
Unit= m/s (squared)
Resultant force =
Newton’s Second Law
Mass x Acceleration
F=ma
Unit = N, Newtons
Weight =
Mass x gravitational field strength
W=mg
Unit = N, Newtons
Momentum =
Mass x velocity
P=mv
Unit= kg m/s
Force =
Momentum
Changing in momentum divided by time
P= (mv-mu)/t
Unit = N, Newtons
Distance travelled =
Average speed x time
D= s x t
Unit= m
Change in gravitational potential energy =
Mass x gravitational field strength x change in height
(change in) GPE=mgh
Unit= J, Joules
Kinetic energy =
1/2 x mass x velocity squared
KE= 1/2 x m x v (squared)
Unit= J, Joules
Efficiency =
Useful energy in divided by total energy out times 100
OR
Useful power divided by total power times 100
Wave speed =
Frequency x wavelength
V= f x wavelength (upside down y )
OR
Distance/ time ( v= x/t )
Unit= m/sWork done =
Force x distance moved in the direction of the force I
E= fd
(FED, Force = Work done x distance )
Unit= J, Joules
Power =
Work done divided by time taken
P= e/t
Unit= W, Watts
Energy transferred =
Electrically
Charge moved x potential difference (voltage)
E= Q x V
Unit= J,Joules
Potential difference (voltage)=
Current (amperes or amps) x resistance (ohms)
V= IR
Unit= V, Volts
Electrical power =
Current x voltage
P=IV
Unit= W,Watts
Energy transferred =
Current x velocity x time
E= IVT ( ITV)
Unit= J,Joules
Stopping distance =
Thinking distance + braking distance
Change in thermal energy =
Mass x specific heat capacity x temperature change
Q= m x c x °c
Unit= J,Joules
Thermal energy =
Mass x specific latent heat
Q= m x L
Unit= J,Joules
Time period =
1 divided by Frequency
1/f
Unit= s, seconds
Frequency =
1 divided by time
1/t
Units= Hz, Hertz
Speed =
Distance / time
V= x/t
Density=
Mass/volume
P= m/v
Units= g/cm(cubed) OR kg/m(cubed)
Final velocity - initial velocity =
2 x acceleration x distance
V squared - u squared = 2ax
Force =
Magnets
Magnetic flux density x current x length ( l )
F= B x I x l
Unit= N, Newtons
Force exerted on a spring=
Spring constant (N/m) x extension (m) F= kx Unit= N,Newtons
Energy transferred in stretching=
1/2 x spring constant x extension squared
E= 1/2 x k x x squared
Unit= J,Joules
Charge=
Current x time
Q= It
Unit= C,Coulombs
Electrical Power =
Current squared x Resistance
P= I^2 x R
Unit= Watts, W
