Assignment Chapters 7 and 8

1. A wave has a frequency of 40 Hz. Calculate the period and the number of cycles present in

60 s. (4 marks)

2. An object undergoes simple harmonic motion with period 4.0 s. What is the acceleration of the

object at a displacement of 1.3 m from the equilibrium position? (3 marks)

3. A pendulum has a period of 1.8 s on the moon. What is the length of the pendulum? (3 marks)

4. A person of mass 70.8 kg hangs upside down from a bungee cord. The cord stretches 1.2 m

when the person is in equilibrium. What is the natural period of oscillation of this person on the

cord? (4 marks)

5. A pendulum on earth has an amplitude of 48.2 cm. If the pendulum is displaced 38.3 cm at a

time of 1.7 s, what is the period of the pendulum, and how long is the pendulum? (4 marks)

6. A ball of mass 0.38 kg is suspended between two springs on board the space shuttle as

illustrated.

It takes a force of 5.3 N to pull the ball 0.21 m to the side. When released, the ball displays

simple harmonic motion. What is the frequency of the motion? (4 marks)

7. The horizontal distance between a crest and an adjacent trough is 0.48 m. The trough travels a

distance of 8.6 m in 3.8 s. What is the period of the wave? (4 marks)

8. The period of a sound wave is 2.27 X 10^-3 s. If the wavelength of the wave is 0.77 m, what

is the speed of the wave? (4 marks)

9. In a string with a standing wave pattern on it, the distance between the 3rd and 6th node is

0.45 m. The wave moves with a speed of 5.0 X 10² cm/s. What is the frequency of the source

of the wave? (3 marks)

10. A rope is 3.2 m in length. The rope is attached at both ends. A standing wave with 5 nodes is

on the rope. What is the wavelength of the wave? If the frequency is 5.0 Hz, what is the

speed of the wave? (3 marks)

11.

A wave is Incident on mirror A at an angle of 30^o to the mirror surface. The wave reflects

off of mirror A onto mirror B and finally onto Mirror C. What is the angle of reflection off of

mirror C, if the angle between mirrors A and B is 120^o, and the angle between mirror B and

C is 100^o? (1 mark)

12. A wave moves from one depth of water to the next. The wave travels 96.0 mm in 3.0 s in the

first medium. The wavelength of the wave in the first medium is 9.00 mm, and 12.00 mm in the

second medium.

a) What is the speed of the wave in the second medium? (3 marks)

b) If the angle of refraction is 27.3^o, what is the angle of Incidence? (2 marks)

13. The wavelength of a wave in the first medium is 9.2 cm. The wave passes into a region where

the frequency of the wave is 25.0 Hz and the speed is 250.0 cm/s.

a) Calculate the critical angle. (2 marks)

b) Describe what happens if the angle of incidence of this wave is 70^o. (1 mark)

14. A wave of wavelength 4.3 cm strikes a barrier with two openings in it. A 3rd order nodal line

is formed at an angle of 60^o. What is the separation of the openings? (3 marks)

15. A wave falls on a barrier with two openings in it that are 3.3 cm apart. A point on the 2nd

nodal line is 25.3 cm from the midpoint between the openings and 4.8 cm from the central

anti nodal line. What is the wavelength of the wave? (3 marks)

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November 22, 2013