Flashcards in Physics - Equations Deck (29):

1

## Acceleration =

###
( final velocity - initial velocity ) divided by time

A= (v-u)/t

Unit= m/s (squared)

2

##
Resultant force =

(Newton’s Second Law)

###
Mass x Acceleration

F=ma

Unit = N, Newtons

3

## Weight =

###
Mass x gravitational field strength

W=mg

Unit = N, Newtons

4

## Momentum =

###
Mass x velocity

P=mv

Unit= kg m/s

5

##
Force =

(Momentum)

###
Changing in momentum divided by time

P= (mv-mu)/t

Unit = N, Newtons

6

## Distance travelled =

###
Average speed x time

D= s x t

Unit= m

7

## Change in gravitational potential energy =

###
Mass x gravitational field strength x change in height

(change in) GPE=mgh

Unit= J, Joules

8

## Kinetic energy =

###
1/2 x mass x velocity squared

KE= 1/2 x m x v (squared)

Unit= J, Joules

9

## Efficiency =

###
Useful energy in divided by total energy out times 100

OR

Useful power divided by total power times 100

10

## Wave speed =

###
Frequency x wavelength

V= f x wavelength (upside down y )

OR

Distance/ time ( v= x/t )

Unit= m/s

11

## Work done =

###
Force x distance moved in the direction of the force I

E= fd

(FED, Force = Work done x distance )

Unit= J, Joules

12

## Power =

###
Work done divided by time taken

P= e/t

Unit= W, Watts

13

##
Energy transferred =

(Electrically)

###
Charge moved x potential difference (voltage)

E= Q x V

Unit= J,Joules

14

## Potential difference (voltage)=

###
Current (amperes or amps) x resistance (ohms)

V= IR

Unit= V, Volts

15

## Electrical power =

###
Current x voltage

P=IV

Unit= W,Watts

16

## Energy transferred =

###
Current x velocity x time

E= IVT ( ITV)

Unit= J,Joules

17

## Stopping distance =

### Thinking distance + braking distance

18

## Change in thermal energy =

###
Mass x specific heat capacity x temperature change

Q= m x c x °c

Unit= J,Joules

19

## Thermal energy =

###
Mass x specific latent heat

Q= m x L

Unit= J,Joules

20

## Time period =

###
1 divided by Frequency

1/f

Unit= s, seconds

21

## Frequency =

###
1 divided by time

1/t

Units= Hz, Hertz

22

## Speed =

###
Distance / time

V= x/t

23

## Density=

###
Mass/volume

P= m/v

Units= g/cm(cubed) OR kg/m(cubed)

23

## Final velocity - initial velocity =

###
2 x acceleration x distance

V squared - u squared = 2ax

24

##
Force =

(Magnets)

###
Magnetic flux density x current x length ( l )

F= B x I x l

Unit= N, Newtons

25

## Force exerted on a spring=

###
Spring constant (N/m) x extension (m)

F= kx

Unit= N,Newtons

26

## Energy transferred in stretching=

###
1/2 x spring constant x extension squared

E= 1/2 x k x x squared

Unit= J,Joules

27

## Charge=

###
Current x time

Q= It

Unit= C,Coulombs

28