Question 1

A mass attached to a spring oscillates with simple harmonic motion. If the spring constant $$k is $$doubled and the mass $$m is $$halved, what happens to the frequency $$f of $$oscillation?

Accepted Answer

The frequency increases by a factor of $$2.$$

Question 2

A pendulum clock is taken from Earth to the Moon, where gravity is lower. If the length $$L of $$the pendulum remains unchanged, how does the period $$T$$ change?

Accepted Answer

The period increases because gravity is weaker.

Question 3

Which of the following best describes the energy transformation in a mass-spring system undergoing simple harmonic motion?

Accepted Answer

Kinetic energy is maximum at equilibrium, and potential energy is maximum at maximum displacement.

Question 4

A string is stretched with tension $$T$$ and has mass per unit length $$\mu. If $$the tension is quadrupled, what happens to the speed $$v of a $$wave on the string?

Accepted Answer

The speed doubles.

Question 5

A sound source moves toward a stationary observer. Which statement about the observed frequency is correct?

Accepted Answer

The observed frequency is higher than the emitted frequency.

Question 6

A wave travels along a string with speed $$v = \sqrt{T/\mu}. If $$the mass per unit length $$\mu is $$doubled and the tension $$T is $$halved, what happens to the wave speed?

Accepted Answer

The speed decreases by a factor of $$2.$$

Question 7

A mass-spring system oscillates with amplitude $$A. $$What is the total mechanical energy $$E of $$the system?

Accepted Answer

$$E = \frac{1}{2}kA^2$

Question 8

A damped oscillator has amplitude $$A(t) = A_0$ e$$^{-t/	au}$$. What happens to the amplitude after a time t$$ = 	au$$?

Accepted Answer

The amplitude is reduced to $$A_0/e$.

Question 9

A loudspeaker emits sound with power $$P. At a $$distance $$r$$ from the speaker, what is the intensity $$I of $$the sound?

Accepted Answer

$$I = \frac{P}{4\pi r^2$}$$

Question 10

A person hears a sound at $$60 dB. If $$the intensity increases by a factor of $$10$$, what is the new decibel level?

Accepted Answer

$$70 dB$$

Question 11

A wave on a string is described by $$y(x,t) = A \cos(kx - \omega t). $$What is the wavelength $$\lambda in $$terms of $$k$$?

Accepted Answer

$$\lambda = \frac{2\pi}{k}$$

Question 12

A child swings on a playground swing (a pendulum). If the length of the swing is increased, what happens to the period $$T$$?

Accepted Answer

The period increases.

Question 13

Which of the following statements about mechanical and electromagnetic waves is correct?

Accepted Answer

Mechanical waves require a medium, electromagnetic waves do not.

Question 14

A mass-spring system is driven at its natural frequency. What phenomenon occurs?

Accepted Answer

Resonance, resulting in large amplitude oscillations.

Question 15

A sound wave has frequency $$f$$ and wavelength $$\lambda. If $$the frequency is doubled in the same medium, what happens to the wavelength?

Accepted Answer

The wavelength is halved.

Question 16

A shock wave is produced when a jet flies faster than the speed of sound. What is the main consequence?

Accepted Answer

A sonic boom is heard.

Question 17

A mass-spring system oscillates with displacement $$x(t) = A \cos(\omega t). $$What is the acceleration $$a(t) at $$time $$t$$?

Accepted Answer

$$a(t) = -\$$omega^2$$ x(t)$$

Question 18

A sound wave travels outward from a point source. If you move twice as far from the source, what happens to the intensity?

Accepted Answer

The intensity decreases by a factor of $$4.$$

Question 19

Which of the following is true about the motion of particles in a sound wave?

Accepted Answer

Particles oscillate parallel to the direction of wave propagation.

Question 20

A string vibrates at frequency $$f$$ and wavelength $$\lambda. If $$the frequency is increased but the string and tension remain unchanged, what happens to the wavelength?

Accepted Answer

The wavelength decreases.

Oscillations, Traveling Waves, and Sound: Study Notes

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드