formulae

Question 1

density

Answer 1

mass/volume

Question 2

velocity

Answer 2

distance/time

Question 3

acceleration

Answer 3

change in velocity/change in time
OR
2as = v^2 - i^2
2acceleration distance = final v^2 - initial v^2

Question 4

weight

Answer 4

mass x gravitational field

Question 5

elastics force

Answer 5

spring (constant) x extension

Question 6

force

Answer 6

mass x acceleration

Question 7

torque (moment)

Answer 7

torque = perpendicular distance x force

Question 8

momentum

Answer 8

mv - mu
mass x velocity

Question 9

impulse

Answer 9

force x time

Question 10

resultant force

Answer 10

change in momentum/change in time

Question 11

kinetic energy

Answer 11

(1/2) x mass velocity^2

Question 12

gravitational potential energy

Answer 12

gravitational energy= mass x gravity x height

Question 13

work

Answer 13

force x distance

Question 14

power

Answer 14

work done/time taken

Question 15

pressure

Answer 15

force/area

Question 16

specific heat capacity

Answer 16

change in energy/ mass x change in temperature

Question 17

refractive index (snells law)

Answer 17

sin(incidence angle)/sin(refracted angle)

Question 18

critical refraction angle

Answer 18

1/sin(critical angle)

Question 19

speed of light

Answer 19

3 x 10^8

Question 20

human hearing frequency range

Answer 20

20Hz - 20kHz

Question 21

speed of sound in air

Answer 21

330 - 350 m/s

Question 22

electric current

Answer 22

charge/ time

Question 23

voltage

Answer 23

work/ charge

Question 24

resistance

Answer 24

voltage / current

Question 25

electrical power

Answer 25

voltage x current

Question 26

electrical energy

Answer 26

current x voltage x time

Question 27

potential divider

Answer 27

resistance 1/ resistance 2 = voltage 1/ voltage 2

Question 28

transformer equation

Answer 28

primary voltage/ secondary voltage = primary number of coils/ secondary number of coils

Question 29

efficiency equation for transformers

Answer 29

primary current x primary voltage = secondary current x secondary voltage

Question 30

power in transformers

Answer 30

current^2 x resistance

Question 31

Charge

Answer 31

Q=IT

Question 32

State what emf is and formula

Answer 32

electrical work done by a source in moving a unit charge around a complete circuit W/Q WORK/CHARGE

Question 33

state what is p.d. and formula

Answer 33

the work done by a unit charge passing through a component W/Q

Question 34

other formula for impulse

Answer 34

m(vf - vi)