year 9 end of years

Question 1

what is the gravitational potential energy equation?

Answer 1

gpe=mgh (mass x gravitational field strength x height

Question 2

what is the kinetic energy equation?

Answer 2

ke=1/2mv^2 (1/2 or 0.5 x mass x velocity squared)

Question 3

what is the equation for power?

Answer 3

power=energy transferred/time taken

Question 4

in the power equation (power=energy transferred/time taken), what are the units?

Answer 4

power = watts, energy transferred = joules - J, time taken = seconds - s

Question 5

in the gpe equation (gpe=mgh), what are the units?

Answer 5

gpe = joules J, mass = kg, gravitational field strength = N - 10N on earth, height = m

Question 6

in the kinetic equation (ke=1/2mv^2), what are the units?

Answer 6

ke = J, mass = kg, speed = m/s

Question 7

what is the work done equation?

Answer 7

w=fd (work done = force x distance moved in the direction of force

Question 8

in the work done equation (w=fd), what are the units?

Answer 8

w=J, f=N, distance=m

Question 9

what is the efficiency equation?

Answer 9

efficiency = useful energy out/total energy in

Question 10

in sankey diagrams, what is put on the top?

Answer 10

useful energy (it goes in an arrow to the right)

Question 11

in sankey diagrams, what is put on the bottom, angling downwards?

Answer 11

wasted energy (it curves down)

Question 12

what is the speed equation?

Answer 12

distance / time

Question 13

what are the units for the speed equation?

Answer 13

speed - m/s, distance - m, time - seconds

Question 14

what is the refractive index equation?

Answer 14

sin i / sin r

Question 15

what is the other refractive index equation?

Answer 15

1 / sin c

Question 16

what is total internal refraction?

Answer 16

when the light bounces back

Question 17

what type of energy does something moving have?

Answer 17

kinetic energy

Question 18

is it true that the colder an object is, the more thermal energy it has?

Answer 18

no, it is: the hotter an object is, the more thermal energy it has

Question 19

what is electrostatic energy?

Answer 19

when 2 charges attract or repel each other

Question 20

what is magnetic energy?

Answer 20

when 2 magnets attract or repel each other

Question 21

can energy be created or destroyed?

Answer 21

no

Question 22

in transverse waves, what direction are the vibrations in?

Answer 22

90* to the direction energy is transferred

Question 23

in longitudinal waves, what direction are the vibrations in?

Answer 23

the same direction as the wave transfers energy

Question 24

what are rarefactions?

Answer 24

when waves are further apart

Question 25

what are compressions?

Answer 25

when waves are closer together

Question 26

what type of wave (transverse or longitudinal) are most waves?

Answer 26

transverse

Question 27

what is the sentence to remember the electromagnetic waves?

Answer 27

Rude Men In Venice Use Xray Goggles

Question 28

what are the 7 electromagnetic waves?

Answer 28

1. radio waves
2. micro-waves
3. infrared
4. visible light
5. ultra-violet
6. x-rays
7. gamma rays

Question 29

do radio waves have a longer or shorter wavelength than the other EM waves?

Answer 29

longer wavelength

Question 30

do gamma rays have a higher or lower frequency than the other EM waves?

Answer 30

higher frequency

Question 31

what is refraction?

Answer 31

the change in direction of a wave as it moves from one medium to another

Question 32

is this true: as the angle of incidence increases, the angle of reflection increases?

Answer 32

yes

Question 33

does i=r?

Answer 33

yes

Question 34

why does refraction occur?

Answer 34

because there is a change in wavespeed