Waves topic 6

Question 1

types of waves + examples

Answer 1

transverse= ripples on water
longitudinal= sound through air

Question 2

explain the difference between transverse and longitudinal

Answer 2

transverse= perpendicular
longitudinal= vibrations parallel to direction of E transfer

Question 3

what’s mechanical wave

Answer 3

causes particle oscillations in solid liquid and gas need a medium to travel through it

Question 4

what’s electromagnetic waves

Answer 4

cause oscillations in electrical+ magnetic fields

Question 5

what do waves do

Answer 5

transfer E

Question 6

describe the features of a wave

Answer 6

amplitude=maximum displacement of a point of a wave point from rest pos (undisturbed and not vibrating)
wavelength= distance between 2 equivalent points on a wave
frequency= number of waves passing a point each second

Question 7

equation for weight of an object

Answer 7

W=mg

Question 8

T=1/f

Answer 8

time period= 1/freq

Question 9

what is wave speed

Answer 9

speed that E is transferred through the medium

Question 10

what’s the equation and units for wave speed

Answer 10

wave speed (m/s)= freq (Hz) x wavelength (m)

Question 11

ripple tank experiment hazard

Answer 11

electrical components near water-> shock
secure components before water + avoid splashes

Question 12

how does sound travel

Answer 12

air particles vibrate and collide with each other, passes sound to the ear drum

Question 13

equation for speed of sound

Answer 13

v= d/t
m/s m/s

Question 14

Experiment for measuring waves in a ripple tank

Answer 14

1. fill ripple tank with 5cm deep water
2. adjust height of wooden rod so it touches water surface
3. switch on lamp and motor- adjust so low freq waves can be observed
4. measure length of several waves and divide by no of waves = wavelength
5. count number of waves passing a point in ten seconds and divide by 10 seconds= frequency
6. calculate speed of waves during wave speed= freq x wavelength

Question 16

what’s contact force+ examples

Answer 16

the objects physically touch
friction, air resistance,tension, normal contact force

Question 17

what’s non contact force

Answer 17

the objects are physically separated
gravitational force,electrostatic force,magnetic force

Question 18

W=FxD

Answer 18

Work done equals force times distance

Question 19

what’s velocity?

Answer 19

the speed of an object in a given direction

Question 20

Newton’s first law

Answer 20

If the resultant force acting on an object is zero and:
the object is stationary, it remains stationary
the object is moving, it continues to move at same speed in same direction

Question 21

Center of mass

Answer 21

weight of mass can act at a single point

Question 22

how are the weight and mass of an object related

Answer 22

they are directly proportional

Question 23

how do u measure weight

Answer 23

newtonmeter, calibrated spring balance

Question 24

resultant force

Answer 24

number of forces act on object replaced with 1 force with the same overall effecr

Answer 25

number of forces act on object replaced with 1 force with the same overall effect

Question 26

longitudinal wave examples

Answer 26

PARALLEL sound ultrasound seismic P waves

Question 27

what is work

Answer 27

F causes object to move to trough a distance——-> work done

Question 28

Equation for work

Answer 28

W= F x D joules , newtons, meters

Question 29

relationship of joules to newton meters

Answer 29

1J= 1N-m

Question 30

what happens when work is done against friction

Answer 30

object rise in temp

Question 31

elastic potential energy

Answer 31

0.5 x spring constant x (extension) ^2

Question 34

how do radio waves reaching aerial produce signals in the electrical circuit of the radio

Answer 34

aerial absorb radio waves aerial e vibrate creates an alternating current radio freq= radio wave freq

Question 36

how can you demonstrate longitudinal waves

Answer 36

push and pull a stretched slinky spring shows compression and rarefaction areas [high p particles close] [low p far apart]

Question 37

what is compression

Answer 37

in longitudinal waves areas of increased p particles closer together>avg what is rare fraction in longitudinal waves areas of reduced pressure particles closer together> avg

Question 38

describe how to measure speed of sound in air

Answer 38

2 people stand 100m apart 1 claps the other starts a stopwatch when they see the clap stop when sound is heard speed= distance/time repeat 3x and calc error= reaction time

Question 40

compressions

Answer 40

high p, particles close together

Question 41

rarefractions

Answer 41

low p , particles are far apart

Question 42

examples of transverse waves

Answer 42

ripples on water surface vibrations guitar string mexican wave electromagnetic waves (light waves)(microwaves)(radio waves) Seismic s wave

Question 43

how can you demonstrate transverse waves

Answer 43

with rope move up and down