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Flashcards in Key equations Deck (24):
1

Average speed =

Distance / time

2

Distance =

Average speed x time

3

Acceleration =
And another version which starts with v^2 - u^2 = ...

Change in velocity / time taken
a= (v-u)/t
V^2 - u^2 = 2 x a x X
X stands for distance

4

What is Newton’s second law? The equation for force?

F=m x a

5

Weight=

Mass x gravitational field strength
W = m x g

6

What is Earths gravitational field strength?

10 N/kg
9.81 rounded

7

Momentum =

Mass (kg) x velocity
P = m x v

8

Change in gravitational potential energy (Joules)=

Mass x gravitational field strength x change in vertical height
^GPE = m x g x ^h

9

Kinetic energy (Joules) =

1/2 x m x v^2

10

Efficiency =

Useful energy transferred / total energy supplied

11

Wave velocity =
State both equations

Wave velocity = frequency x wavelength
Wave velocity = distance / time

12

What is the equation for force which includes momentum ?

Force = change in momentum / time
F = (mv - mu) / t

13

What is the equation for work done?

Work done = force x distance

14

What is the equation for power? A measure of how quickly work done is being done

Power = work done / time

15

What is the equation for work done (measured in joules) ?

E = F x d
Work done in Joules= force in N x distance moved in direction of force

16

What is the equation for power in watts?

P = E/t
Power = Energy transferred in joules / time

17

What is the equation for energy transferred in joules?

E = Q x V
Energy transferred in joules = Charge in coulombs x potential difference in volts

18

What is the equation for potential difference in volts?

V = I x R
Potential difference in volts = current in amps resistance in Ohms

19

What is the equation for charge in coulombs (C)?

Q = I x t
Charge in coulombs = current in amps x time

20

What is the equation (one out of 2) for power in watts, including potential difference in volts?

P = I x V
Power in watts = current in amps x potential difference in volts

21

What is the equation (one out of 2) for power in watts,including resistance in ohms (measured with Greek letter Omega)?

P = I(squared) x R
Power in watts = current in amps (squared) x resistance in ohms

22

What is the equation for density in kg/m(cubed) or g/cm(cubed)?

p (lower case Greek letter rho) = m / V
Density in kg/m(cubed) or g/cm(cubed) = mass in kg/ volume in m or cm (cubed)

23

What is the equation for pressure in N/m(squared) or N/cm(squared)?

P = F/ A
Pressure in N/m or N/cm (squared) = Force in N / Area in m or cm (squared)

24

What is the equation for Force in N, including spring constant and extension?

F = k x X
Force in N = spring constant (in N/m, N/cm or N/mm) x extension (in m, cm or mm)