Question 1

A pendulum is used to measure time intervals. If the length of the pendulum is doubled, how does the period change? Use the formula $$T = 2\pi \sqrt{\frac{L}{g}}.$$

Accepted Answer

The period increases by a factor of $$\sqrt{2}.$$

Question 2

A sound wave travels at a speed of 340 m/s and has a frequency of 1700 Hz. What is its wavelength? Use $$v = f\lambda.$$

Accepted Answer

$$0.2\ \mathrm{m}$$

Question 3

Two waves of frequencies 440 Hz and 444 Hz interfere. What is the beat frequency produced?

Accepted Answer

$$4\ \mathrm{Hz}$$

Question 4

A ship uses sonar to measure the depth of the ocean. If the speed of sound in water is $$1500\ \mathrm{m/s}$$ and the echo returns after 4 seconds, what is the depth of the ocean?

Accepted Answer

$$3000\ \mathrm{m}$$

Question 5

A closed air column resonates at its fundamental frequency. If the length of the column is $$0.25\ \mathrm{m}$$, what is the wavelength of the sound produced?

Accepted Answer

$$1.0\ \mathrm{m}$$

Question 6

A light ray passes from air ($$n=1.00) $$into water ($$n=1.33) at an $$angle of incidence of $$30^\circ. $$What is the angle of refraction in the water? Use Snell's Law: $$n_1$$ \sin \$$theta_1$$ = $$n_2$$ \sin \$$theta_2.$$

Accepted Answer

$$22.1^\circ$$

Question 7

If the intensity of light at a distance $$r$$ from a source is $$I$$, what will be the intensity at a distance $$2r$$ from the same source? Use the inverse square law: $$I \propto \frac{1}{r^2$}.$$

Accepted Answer

$$\frac{I}{4}$$

Question 8

A tuning fork of frequency 400 Hz is struck with another fork, and 20 beats are counted in 10 seconds. What are the possible frequencies of the second fork?

Accepted Answer

380 Hz or 420 Hz

Question 9

A wave on a string has a speed of 25 m/s and a wavelength of 0.5 m. What is its frequency?

Accepted Answer

$$50\ \mathrm{Hz}$$

Question 10

A block of cubic zirconia ($$n=2.20) is $$placed in water ($$n=1.33). A $$laser beam passes from water into the zirconia at an angle of incidence of $$45^\circ. $$What is the angle of refraction inside the zirconia? Use Snell's Law.

Accepted Answer

$$24.1^\circ$$

Question 11

A pipe closed at one end and open at the other resonates at its fundamental frequency. If the length of the pipe is $$0.5\ \mathrm{m}$$, what is the wavelength of the sound produced?

Accepted Answer

$$2.0\ \mathrm{m}$$

Question 12

A sound wave travels through air at $$20^\circC. $$What is the speed of sound? Use $$v = 331 + 0.6T$$ where $$T is in$$ $$^\circC.$$

Accepted Answer

$$343\ \mathrm{m/s}$$

Question 13

Two identical waves traveling in opposite directions on a string produce a standing wave. What is the distance between adjacent nodes?

Accepted Answer

$$\frac{\lambda}{2}$$

Question 14

A light ray passes from glass ($$n=1.50) $$into air ($$n=1.00) at an $$angle of $$45^\circ. $$What is the critical angle for total internal reflection?

Accepted Answer

$$41.8^\circ$$

Question 15

A person hears a sound with a frequency of 1000 Hz and a wavelength of 0.34 m. What is the speed of sound in this medium?

Accepted Answer

$$340\ \mathrm{m/s}$$

Question 16

A tuning fork of frequency 512 Hz is used to produce beats with another fork. If 8 beats are heard in 2 seconds, what are the possible frequencies of the second fork?

Accepted Answer

504 Hz or 520 Hz

Question 17

A wave on a string has an amplitude of 0.05 m and a frequency of 10 Hz. If the wave speed is 2 m/s, what is the wavelength?

Accepted Answer

$$0.2\ \mathrm{m}$$

Question 18

A light ray passes from air into diamond ($$n=2.42) at an $$angle of $$30^\circ. $$What is the angle of refraction inside the diamond?

Accepted Answer

$$12.0^\circ$$

Question 19

A pipe open at both ends resonates at its fundamental frequency. If the length of the pipe is $$0.75\ \mathrm{m}$$, what is the wavelength of the sound produced?

Accepted Answer

$$1.5\ \mathrm{m}$$

Oscillations, Waves, and Sound: Study Notes and Problem Set

Study Guide - Practice Questions

Study Guide - Flashcards