/35 marks Name:

Jan:2015

WAVES UNIT TEST

Part 1: Multiple Choice (1 mark each)

1. A transverse waves passes along a stretched slinky. Each coil of the spring will move

a) In circles

b) In ellipses

c) Parallel to direction of travel

d) Perpendicular to direction of travel

2. A sound wave is an example

a) Transverse wave

b) Longitudinal wave

c) Standing wave

d) Shock wave

3. The number of wave crests passing a point per second is called:

a) Period

b) Frequency

c) Amplitude

d) Wavelength

e) Velocity

4. From the diagram below, which lengths represent the wavelength and the amplitude, in that

order.

a) X and Z

b) W and Y

c) X and Y

d) W and Z

5. A wave that has a frequency of 5.0 Hz and a speed of 10 m/s has a wavelength of

a) 50 m b) 2.0 m c) 0.50 m d ) 0.20m

6. A wave has a frequency of 50 Hz. The period of the wave is

a) 0.02 s

b) 0.2 s

c) 2 s

d) 20 s

7. What is the frequency of a water wave that has a speed of 0.4 m/s and a wavelength of 0.02 m

a) 10 Hz

b) 20 Hz

c) 0.008 Hz

d) 0.05 Hz

8. A boat at anchor is rocked by waves with a speed of 10 m/s. These waves are 40 m apart, and

would reach the boat once every

a) 400 s

b) 4 s

c) 30 s

d) 0.25 s

9. Consider the wave diagram below. Which labels represent the angles of incidence and

reflection, in that order?

a) d & a

b) a & d

c) c & b

d) b & c

10. When waves change direction when passing from one medium to another, this is called…

a) Reflection

b) Refraction

c) Diffraction

d) Interference

11. The following diagram illustrates water waves passing though an opening in a barrier. This is an

example of

a) Reflection

b) Refraction

c) Diffraction

d) Interference

12. When two waves cross each other, maximum destructive interference will occur in places

where waves have

a) Two crests meeting

b) A crest and a trough meeting

c) A crest and a node meeting

d) A node and an antinode meeting

13. Which pair of pulses will produce constructive interference?

14. The velocity of sound waves in cold air is 320 m/s, and in warm air is 380 m/s. If the wavelength

of the sound was 2.0 m in the cold air, what would the wavelength be in the warm air?

a) 0.42 m

b) 0.59 m

c) 1.68 m

d) 2.38 m

15. The speed of a wave refers to

a) how often it vibrates to and fro. b) how high it vibrates. c) how much time it takes to vibrate to and fro. d) how far a given point (e.g., a crest) on the wave travels per unit of time.

16. As the frequency of a wave increases, the period of the wave ___________.

a) decreases b) increases c) remains the same

17. Light will undergo total internal reflection only when it _______.

a) exceeds the critical angle b) does not exceed the critical angle c.) when it is equal to the critical angle d) none of the above

18. A critical angle can only exists when a wave ___________. a) passes from a material of lower density to material of higher density b) passes from a material of higher density to a material of lower density c) passes between materials of equal densities d) reaches the speed of total internal reflection

19. Which option describes a standing wave?

Waves Direction Medium

a) Identical Same Same

b) Non-identical Opposite Different

c) Identical Opposite Same

d) Non-identical Same Different

20. A tuning fork vibrates 2.4E4 times in 2.00 minutes. What is the frequency of the vibration in Hz?

a) 12 000 Hz

b) 8.3 E-5 Hz

c) 200 Hz

d) 5.0 E-3 Hz

Part 2: Short Answer

1. Jedrek and RJ are floating on top of the water near the end of the pool when Juliian announces

his presence with a massive cannonball. The resulting tidal wave travels the length of the pool

and back in 25 seconds. The pool is 25 meters long. Determine the speed of the wave. (2 marks)

2. The period of a wave is 0.03 seconds. It travels at a velocity of 10.0 m/s. Determine the

frequency and the wavelength of the wave. (2 marks)

3. a)An incident ray in air (n=1.0) is approaching the boundary with an unknown material at an

angle of incidence of 61.6°. The angle of refraction is 41.4°. Determine the index of refraction of

the unknown material. (2 marks)

b.) If the light ray is reversed and now travels from the unknown material into air, determine

the critical angle. (2 marks)

4. a) Sketch the waves as they might appear after they undergo the interaction shown /1mark

(wave viewed

from above)

b)Sketch the waves as they might appear after they undergo the interaction shown /1 mark

(waves as (sea wall or concrete

viewed from barrier)

above)

5. In words AND by drawing, describe the difference between longitudinal and transverse waves

/2 marks

6. Two boats are anchored 7.0 meters apart. They bob up and down, returning to the same up

position every 10.0 seconds. The boats rise a vertical distance of 7.0 meters between their

lowest and their highest point. When one is up the other is down. There are never any wave

crests between the boats. Determine the period, frequency, wavelength, amplitude and speed

of the waves. (5 marks)

7. By means of a paragraph, point-form or illustration(perhaps all three), clearly explain one of the

following wave phenomena. Three significant points are expected for full marks. (3 marks)

How is light both a wave and a particle?

Why is the sky blue?

Why does one hear the bass at a distant house party rather than the treble?

Describe the Doppler effect?

Explain the differences and similarities of the notes on a musical scale