When timing the 100-m run, officials at the finish line are instructed to start their stopwatches at the sight of smoke from the starter’s pistol and not at the sound of its firing. Explain. What would happen to the times for the runners if the timing started when sound was heard?

Does the Doppler shift occur for only some types of waves or for all types of waves?

A fire truck is moving at 35 m/s, and a car in front of the truck is moving in the same direction at 15 m/s. If a 327-Hz siren blares from the truck, what frequency is heard by the driver of the car?

A baseball fan on a warm summer day $\left(30^{\circ} \mathrm{C}\right)$ sits in the bleachers 152 m away from home plate. a. What is the speed of sound in air at $30^{\circ} \mathrm{C}$? b. How long after seeing the ball hit the bat does the fan hear the crack of the bat?

A rock band plays at an 80-dB sound level. How many times greater is the sound pressure from another rock band playing at each of the following sound levels? a. 100 dB b. 120 dB

A sound wave has a frequency of 4700 Hz and travels along a steel rod. If the distance between compressions, or regions of high pressure, is 1.1 m, what is the speed of the wave?

Circle the BEST answer.
To use PPE correctly
a Never change gloves in the person's room
b Tie a gown's waist strings in front
c Don gloves first when applying PPE
d Apply new PPE for each person

Find the frequency of a sound wave moving through iron at $25^{\circ} \mathrm{C}$ with a wavelength of 1.25 m.

The sound from a trumpet travels at 351 m/s in air. If the frequency of the note is 298 Hz, what is the wavelength of the sound wave? A. $9.93 \times 10^{-4} \mathrm{m}$ B. 0.849 m C. 1.18 m D. $1.05 \times 10^{5} \mathrm{m}$

Strike a tuning fork with a rubber hammer and hold it at arm’s length. Then press its handle against a desk, a door, a filing cabinet, and other objects. What do you hear? Why?

A sound source plays middle C (262 Hz). How fast would the source have to go to raise the pitch to C sharp (271 Hz)? Use 343 m/s as the speed of sound.

How does a spring pulse reflected from a rigid wall differ from the incident pulse?

A tuning fork produces three beats per second with a second, 392-Hz tuning fork. What is the frequency of the first tuning fork?

A bugle can be thought of as an open pipe. If a bugle were straightened out, it would be 2.65-m long. a. If the speed of sound is 343 m/s, find the lowest frequency that is resonant for a bugle (ignoring end corrections). b. Find the next two resonant frequencies for the bugle.