final review

An organ pipe with a fundamental frequency f is open at both ends. If one end is closed off, the fundamental frequency will drop by half. not change. double.

drop by half.

Do you expect an echo to return to you more quickly on a hot day or a cold day? Hot day. Cold day. Same on both days.

Hot day.

The sound level near a noisy air conditioner is 70 dB. If two such units operate side by side, the sound level near them would be 70 dB. 73 dB. 105 dB. 140 dB.

73 dB

At time t = 0 an object is traveling to the right along the + x axis at a speed of 10.0 m/s with acceleration −2.0 m/s2. Which statement is true? The object will slow down, eventually coming to a complete stop. The object cannot have a negative acceleration and be moving to the right. The object will continue to move to the right, slowing down but never coming to a complete stop. The object will slow down, momentarily stopping, then pick up speed moving to the left.

.The object will slow down, momentarily stopping, then pick up speed moving to the left.

You are in the middle of a large field. You walk in a straight line for 100 m, then turn left and walk 100 m more in a straight line before stopping. When you stop, you are 100 m from your starting point. By how many degress did you turn? 90°. 120°. 30°. 180°. This is impossible. You cannot walk 200 m and be only 100 m away from where you started.

120°.

two loudspeakers are about 10m apart in the front of a large classroom. If either speaker plays a pure tone at a single frequency of 400 Hz, the loudness seems pretty even as you wander around the room, and gradually decreases in volume as you move farther from the speaker. If both speakers play the same tone together, what do you hear as you wander around the room?a) The pitch of the sound increases to 800 Hz, and the sound is louder but not twice as loud. It is louder closer to the speakers and gradually decreases as you move away from the speakers - except near the back wall, where a slight echo makes the sound louder.b) The sound is louder but maintains the same relative spatial pattern of gradually decreasing volume as you move away from the speakers.c) As you move around the room, some areas seem to be dead spots with very little sound, whereas other spots seem to be louder than with only one speaker.d) The sou

As you move around the room, some areas seem to be dead spots with very little sound, whereas other spots seem to be louder than with only one speaker.

When a sound wave passes from air into water, what properties of the wave will change? Frequency. Wavelength. Wave speed. Both frequency and wavelength. Both wave speed and wavelength.

Both wave speed and wavelength.

Sound waves are transverse waves characterized by the displacement of air molecules. longitudinal waves characterized by the displacement of air molecules. longitudinal waves characterized by pressure differences. Both (b) and (c). (a), (b), and (c).

Both (b) and (c).

To make a given sound seem twice as loud, how should a musician change the intensity of the sound? Double the intensity. Halve the intensity. Quadruple the intensity. Quarter the intensity. Increase the intensity by a factor of 10.

Increase the intensity by a factor of 10.

You drive 4 km at 30 km/h and then another 4 km at 50 km/h. What is your average speed for the whole 8-km trip? More than 40 km/h. Equal to 40 km/h. Less than 40 km/h. Not enough information.

Less than 40 km/h.

In which of the following is the wavelength of the lowest vibration mode the same as the length of the string or tube? A string. An open tube. A tube closed at one end. All of the above. None of the above.

None of the above.

A ball is dropped from the top of a tall building. At the same instant, a second ball is thrown upward from the ground level. When the two balls pass one another, one on the way up, the other on the way down, compare the magnitudes of their acceleration: The acceleration of the dropped ball is greater. The acceleration of the ball thrown upward is greater. The acceleration of both balls is the same. The acceleration changes during the motion, so you cannot predict the exact value when the two balls pass each other. The accelerations are in opposite directions.

The acceleration of both balls is the same.

One ball is dropped vertically from a window. At the same instant, a second ball is thrown horizontally from the same window. Which ball has the greater speed at ground level? The dropped ball. The thrown ball. Neither--they both have the same speed on impact. It depends on how hard the ball was thrown.

The thrown ball.

A musical note that is two octaves higher than a second note has twice the frequency of the second note. has four times the frequency of the second note. has twice the amplitude of the second note. is 3 dB louder than the second note. None of the above.

has four times the frequency of the second note.

A guitar string vibrates at a frequency of 330 Hz with wavelength 1.40 m. The frequency and wavelength of this sound in air (20°C) as it reaches our ears is same frequency, same wavelength. higher frequency, same wavelength. lower frequency, same wavelength. same frequency, longer wavelength. same frequency, shorter wavelength.

same frequency, shorter wavelength.

You are driving at 75 km/h. Your sister follows in the car behind at 75 km/h. When you honk your horn, your sister hears a frequency higher than the frequency you hear. lower than the frequency you hear. the same as the frequency you hear. You cannot tell without knowing the horn's frequency.

the same as the frequency you hear.

A guitar player shortens the length of a guitar's vibrating string by pressing the string straight down onto a fret. The guitar then emits a higher-pitched note, because the string's tension has been dramatically increased. the string can vibrate with a much larger amplitude. the string vibrates at a higher frequency.

the string vibrates at a higher frequency.

A ball is thrown straight up. What are the velocity and acceleration of the ball at the highest point in its path? v = 0, a = 0. v = 0, a = 9.8 m/s2 up. v = 0, a = 9.8 m/s2 down. v = 9.8 m/s up, a = 0. v = 9.8 m/s down, a = 0.

v = 0, a = 9.8 m/s2 down.

In which of the following cases does a car have a negative velocity and a positive acceleration? A car that is traveling in the

− x direction decreasing in speed.