Physics keywords

Question 1

P1.4 Density =

Answer 1

mass / volume

Question 2

P1.5 (resultant) Force =

Answer 2

mass x acceleration

Question 3

P1.5 Hooke’s law

Answer 3

F = kx (k is spring constant)

Question 4

P1.5 friction

Answer 4

force between two surfaces which impedes motion and results in heating

Question 5

P1.5.2 moment =

Answer 5

force x perpendicular distance from the pivot

Question 6

P1.5.2 equilibrium

Answer 6

no resultant force and no resultant turning effect

Question 7

P1.5.4 Pressure =

Answer 7

force / area

Question 8

P2.2 kinetic energy =

Answer 8

0.5 x m x v^2

Question 9

P2.2 GPE (gravitational potential energy) =

Answer 9

mgh

Question 10

P2.2 change in GPE =

Answer 10

m x g x change in h

Question 11

P2.4 sun is the source of ____ for all our ____ resources, except 3 which are..

Answer 11

energy, energy,
geothermal, nuclear, tidal

Question 12

P2.4 source of tidal energy

Answer 12

mainly the moon

Question 13

P2.4 energy is releases by ____ in the Sun

Answer 13

nuclear fusion

Question 14

P2.4 efficiency of energy = (formula

Answer 14

(useful energy output / energy input)
x 100%

Question 15

P2.4 efficiency of power = (formula

Answer 15

(useful power output / power input)
x 100%

Question 16

P4.3 speed of electromagnetic waves in a vacuum

Answer 16

3.0 x 10^8 m/s

Question 17

P4.4 approximate range of audible frequencies for a healthy human ear

Answer 17

20Hz to 20000Hz

Question 18

P5.2 unlike charges ____, like charges ____

Answer 18

attract , repel

Question 19

P5.2 electric field

Answer 19

region in which an electric charge experiences a force

Question 20

P5.2.2 Current :

Answer 20

rate of flow of charge,
I = Q (charge) / T

Question 21

P5.2.2 current in metals is due to ..

Answer 21

a flow of electrons

Question 22

P5.2.2 A flow of electrons causes a _____ in metals

Answer 22

current

Question 23

P5.2.3 Resistance =

Answer 23

p.d / current

= V / I

Question 24

P2.1 Work done =

Answer 24

force x distance

Question 25

P4 speed =

Answer 25

frequency x wavelength

Question 26

P4 speed

Answer 26

distance the wave travels in 1s

Question 27

P4 frequency

Answer 27

number of complete waves that go past each second (unit : Hz)

Question 28

P4 wavelength

Answer 28

(of a transverse wave) : distance between two adjacent peaks / troughs of the wave

Question 29

P4 amplitude

Answer 29

(of a water wave) maximum displacement of the water from undisturbed position. // half the crest-to-trough height

Question 30

P4 wavefront

Answer 30

moving line that joins all the points on the crest of a wave

Question 31

Principle focus

Answer 31

point where the parallel light rays arriving along the axis of the lens all cross over

Question 32

focal length

Answer 32

the distance at which principal focus happens // distance between principal focus and the centre of the lens

Question 33

speed of electromagnetic waves in a vacuum

Answer 33

3.0 x 10^8 m/s

Question 34

speed of electromagnetic waves in a ___ is 3.0 x 10^8 m/s

Answer 34

vacuum

Question 35

speed of ______ waves in a vacuum is 3.0 x 10^8 m/s

Answer 35

electromagnetic

Question 36

use of radio waves

Answer 36

radio, television communications

Question 37

use of microwaves

Answer 37

satellite television & telephones

Question 38

use of infrared

Answer 38

electrical appliances, remote controllers for televisions, intruder alarms

Question 39

use of X-rays

Answer 39

medicine, security

Question 40

all electromagnetic waves travel with..

Answer 40

same high speed in a vacuum and approximately same in air

Question 41

solidification

Answer 41

substance changes from liquid to solid

Question 42

condensation

Answer 42

substance changes from gas to liquid

Question 43

electromagnetic force (e.m.f)

Answer 43

energy supplied by the source per unit charge in driving the charge round a complete circuit

Question 44

P7.3 current-carrying coil in a magnetic field experiences a _____

Answer 44

turning effect

Question 45

____coil in a magnetic field experiences a turning effect

Answer 45

current-carrying

Question 46

current-carrying coil in a _______ experiences a turning effect

Answer 46

magnetic field

Question 47

how can a turning effect increase

Answer 47

increasing the number of turns on the coil, increasing the current, increasing the strength of the magnetic field