1.       F

What do we call it when sounds bounce back from hard surfaces?

echoes     
                                                       

2.       F/H

what is refraction?

When rays of light change direction when they cross the boundary between one transparent substance and another

3.       F/H

Draw a diagram to show what happens to rays of light when they cross the boundary between air and glass

air                   glass

4.       F/H

Sounds can also be refracted - true or false?

TRUE  

5.       F/H

How do we measure the amplitude of a wave?

the maximum disturbance caused by a wave  

6.       F/H

what do we call the distance between a particular point on a wave and the same point on the next?

wavelength       
                                               

7.       F/H

what is frequency?

number of waves each second produced by a source  

8.       F/H

Waves transfer energy from a source to other places with matter being transferred - true or false?

false - no matter is transferred  

9.       F/H

what causes a change in the direction of water waves when they cross the boundary between two different substances?

a change in speed           
                                           

10.   F/H

When a ray of light travels from glass, 'Perspex' or water into air, all of the wave is refracted - true or false?

false - some is reflected  

11.   F/H

If the angle between the ray and a normal is greater than a certain angle (called the critical angle), all of the light is refracted inside the glass, 'Perspex' or water. This is called total internal reflection - true or false?

false - it's REFLECTED inside the glass  

12.   F/H

what is an optical fibre?

all the light may stay inside the fibre until it emerges from the other end - light travels down optical fibres by repeated total internal reflection.

13.   F/H

describe a use for total internal reflection

fibre optic communications, medical exploration - needs a description

14.   H

are sound waves longitudinal or transverse?

longitudinal  

15.   H

describe the difference between transverse and longitudinal waves

transverse: wave motion is at right angles to the movement of the wave particles - longitudinal: wave motion is along the same line as the motion of the wave particles

16.   H

light waves can travel throught a vacuum - true or false?

TRUE

17.   H

light waves are longitudinal - true or false?

false - transverse

18.   H

wave speed is related to frequency and wavelength by an equation - what is it?

wave speed = frequency x wavelength

19.   H

what is diffraction?

When a wave moves through a gap,  or past an obstacle,  it spreads out from the edges

20.   H

can electromagnetic waves and sound waves be diffracted?

yes - both of them - which is good eveidence that they travel as waves

21.   H

give an example of the diffraction of sound:

sounds can sometimes be heard in the shadow of buildings; radio signals can sometimes be received in the shadow of hills  

22.   H

The extent of this diffraction depends upon the wavelength of the waves - true or false?

TRUE