Physics of Sound & Music Final Exam

A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is A) 0. B) 4.9. C) infinite. D) 9.8. E) none of these

A) 0

By what factor does the intensity of a sound have to increase so that the sound intensity level (SIL) increases by 10dB? A) 10 B) 1 C) 1/10 D) 100

A) 10

A baseball player bats a ball with a force of 1000 N. The reaction force that the ball exerts against the bat is A) 1000 N. B) less than 1000 N. C) more than 1000 N. D) impossible to determine

A) 1000 N

A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second. What is the mass of the car? A) 1500 kg B) 500 kg C) 3000 kg D) 1000 kg E) none of these

A) 1500 kg

A ball is moving at 3 m/s and has a momentum of 48 kg m/s. What is the ball's mass? A) 16 kg B) 12 kg C) 144 kg D) 4 kg E) none of these

A) 16 kg

A horse gallops a distance of 10 kilometers in a time of 30 minutes. Its average speed is A) 20 km/h. B) 40 km/h. C) 15 km/h. D) 30 km/h.

A) 20 km/h.

A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is A) 300 N upward. B) 500 N upward. C) 300 N downward. D) 800 N downward. E) 500 N downward.

A) 300 N upward

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is A) 3000 N B) 30 N C) 300 N D) more than 3000 N

A) 3000 N

A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope? A) 400 N B) 800 N C) 600 N D) zero E) none of these

A) 400 N

If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be A) 9.8 meters per second per second. B) greater than 9.8 meters per second per second. C) less than 9.8 meters per second per second.

A) 9.8 meters per second per second.

Your weight is A) the gravitational attraction force between you and the Earth. B) equal to your mass. C) a property of mechanical equilibrium. D) all of these

A) The gravitational attraction force between you and the Earth

When 2 sine waves that are 180Ŵ out of phase are added together, the amplitude of the sum is A) always zero B) always less than the amplitude of either wave C) equal to the magnitude of the smaller wave D) always less than the amplitude of the larger wave E) always greater than the amplitude of the smaller wav

A) always zero

The least energy required to produce forced vibration in an object occurs A) at its natural frequency. B) below its natural frequency. C) above its natural frequency.

A) at its natural frequency.

If no external forces are acting on a moving object, it will A) continue moving at the same velocity. B) continue moving at the same speed. C) move slower and slower until it finally stops

A) continue moving at the same velocity.

The ossicles are connected to A) eardrum and cochlea B) pinna and middle ear C) cochlea and auditory nerve D) organ of Corti and the Eustachian tube

A) eardrum and cochlea

The quality of a musical note has to do with its A) harmonics. B) loudness. C) amplitude. D) frequency. E) All of the above choices are correct.

A) harmonics

A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second A) is 9.8. B) depends on the height of the cliff. C) is less than 9.8. D) is more than 9.8.

A) is 9.8

For an action force, there must be a reaction force that A) is exactly equal in magnitude. B) is slightly smaller in magnitude than the action force. C) is slightly larger in amplitude than the action force. D) always acts in the same direction

A) is exactly equal in magnitude.

Two tennis balls fall through the air from a tall building. One of them is filled with lead pellets. The ball to reach the ground first is the A) lead-filled ball. B) regular ball. C) same for both

A) lead-filled ball

A sound source of high frequency emits a high A) pitch. B) amplitude. C) speed. D) all of these E) none of these

A) pitch

The speed of a sound wave in air depends on A) the air temperature. B) its wavelength. C) its frequency. D) All of the above choices are correct. E) None of the above choices are correc

A) the air temperature

A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is A) the same for both. B) greater on the bug. C) greater on the car.

A) the same for both

When a rock thrown straight upwards gets to the exact top of its path, its A) velocity is zero and its acceleration is about 10 meters per second per second. B) velocity is zero and its acceleration is zero. C) velocity is about 10 m/s and its acceleration is about 10 meters per second per second. D) velocity is about 10 m/s and its acceleration is zero. E) none of these

A) velocity is zero and its acceleration is about 10 meters per second per second.

The force required to maintain an object at a constant velocity in free space is equal to A) zero. B) the force required to stop it. C) the weight of the object. D) the mass of the object. E) none of these

A) zero

A piano tuner knows that a key on the piano is tuned to the frequency of his tuning fork when he strikes them at the same time and the number of beats he hears each second is A) 4. B) 0. C) 3. D) 1. E) 2.

B) 0.

A 340-hertz sound wave travels at 340 m/s in air with a wavelength of A) 10 m. B) 1 m. C) 100 m. D) 1000 m. E) None of the above choices are correct

B) 1 m.

Compared to a sound of 30 decibels, a sound of 60 decibels is A) 10,000 times as intense. B) 1000 times as intense. C) 100 times as intense. D) 10 times as intense. E) twice as intense.

B) 1000 times as intense.

The approximate range of human hearing is A) 40 hertz to 40,000 hertz. B) 20 hertz to 20,000 hertz. C) 10 hertz to 10,000 hertz. D) Actually all of these - depends on the hearing ability of the person.

B) 20 hertz to 20,000 hertz.

A ride on a roller-coaster car containing 6 passengers takes 3 minutes. Neglecting friction, a similar ride with 12 passengers aboard would take A) 18 minutes. B) 3 minutes. C) 6 minutes. D) 1.5 minutes.

B) 3 minutes

A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is A) zero. B) 3000 N. C) 1500 N. D) 6000 N.

B) 3000 N

) A 5000-kg freight car runs into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg car? A) 5 m/s B) 6 m/s C) 4 m/s D) 8 m/s E) none of these

B) 6 m/s

A kilogram is a measure of an object's A) size. B) mass. C) force. D) weight.

B) Mass

A Mack truck and a Volkswagen traveling at the same speed have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the A) same for both. B) Volkswagen. C) Mack truck

B) Volkswagen

doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. In this way the average force your body experiences is A) less than 1/10 as great. B) about 1/10 as great. C) about 10 times as great. D) more than 1/10 as great.

B) about 1/10 as great

What is the SIL at the threshold of pain? A) about 20 dB B) about 120dB C) about 200 dB D) about 0dB E) about -100d

B) about 120dB

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft? A) about 120 m B) about 180 m C) more than 200 m D) about 60 m

B) about 180 m

If the mass of an object does not change, a constant net force on the object produces constant A) velocity. B) acceleration. C) both of these D) neither of these

B) acceleration

Disregarding air resistance, objects fall with constant A) speed. B) acceleration. C) velocity. D) distances each successive second.

B) accelereation

Hang from a pair of gym rings and the upward support forces of the rings will always A) each equal your weight. B) add up to equal your weight. C) each be half your weight.

B) add up to equal your weight.

The loudness of a musical sound is a measure of the sound wave's A) wavelength. B) amplitude. C) frequency. D) speed. E) all of these

B) amplitude

Your car is coasting on level ground at 60 km/h and you apply the brakes until the car slows to 40 km/h. If you suddenly release the brakes now, the car tends to A) decrease in speed if no other forces act. B) continue moving at 40 km/h. C) momentarily regain its higher initial speed

B) continue moving at 40 km/h

The newton is a unit of A) density. B) force. C) mass. D) inertia.

B) force

A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is A) greater on the automobile. B) the same for both. C) greater on the baby carriage.

B) greater on the automobile

A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun A) because momentum is conserved. B) if the mass of the bullet equals the mass of the gun. C) because both velocity and momentum are conserved. D) because velocity is conserved. E) none of these

B) if the mass of the bullet equals the mass of the gun.

If an object's mass is decreasing while a constant force is applied to the object, the acceleration A) remains the same. B) increases. C) decreases.

B) increases

In science, facts A) mean very little. B) may change. C) are more important than theories. D) are absolute.

B) may change.

Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has a greater A) speed. B) momentum. C) acceleration. D) all of these E) none of these

B) momentum

When you tune a radio to a certain station, you match the frequency of the internal electrical circuit to the frequency of the wanted radio station. In so doing you are employing the principle of A) reverberation. B) resonance. C) beats. D) forced vibrations. E) wave interference

B) resonance

A rifle recoils while firing a bullet. The speed of the rifle's recoil is small because the A) force against the rifle is smaller than against the bullet. B) rifle has much more mass than the bullet. C) momentum of the rifle is smaller. D) momentum is mainly concentrated in the bullet.

B) rifle has much more mass than the bullet.

It is correct to say that impulse is equal to A) the force multiplied by the distance the force acts. B) the change in momentum it produces. C) momentum. D) velocity multiplied by time.

B) the change in momentum it produces

The attraction of a person's body toward Earth is called weight. The reaction to this force is A) the person's body pushing against Earth's surface. B) the person's body pulling on the Earth. C) the Earth's surface pushing against the person's body. D) none of these

B) the person's body pulling on the Earth.

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is A) zero. B) the same. C) one sixth as much. D) six times as much.

B) the same

Compressions and rarefactions normally travel in A) opposite directions in a wave. B) the same direction in a wave. C) directions that are at right angles to the wave direction.

B) the same direction in a wave.

Sound refraction depends on the fact that the speed of sound is A) constant. B) variable. C) inversely proportional to wavelength. D) proportional to frequency. E) None of the above choices are correct

B) variable.

While an object near the Earth's surface is in free fall, its A) acceleration increases. B) velocity increases. C) mass decreases. D) mass increases.

B) velocity increases

An apple at rest weighs 1 N. The net force on the apple when it is in free fall is A) 9.8 N. B) 0.1 N. C) 1 N. D) 0 N. E) none of these

C) 1 N

Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide and stick. The combined mass moves at A) 1.5 m/s. B) 1/6 m/s. C) 1/2 m/s. D) 1/3 m/s. E) 3/4 m/s.

C) 1/2 m/s.

The force of friction on a sliding object is 10 newtons. The applied force needed to maintain a constant velocity is A) less than 10 N. B) more than 10 N. C) 10 N.

C) 10 N

A push on a 1-kg brick accelerates it. Neglecting friction, to equally accelerate a 10-kg brick, one would have to push with A) just as much force. B) one-tenth the amount of force. C) 10 times as much force. D) 100 times as much force. E) none of these

C) 10 times as much force

If a rocket initially at rest accelerates at a rate of 50 m/s2 for one minute, its speed will be A) 500 m/s. B) 50 m/s. C) 3000 m/s. D) 3600 m/s.

C) 3000 m/s.

An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The magnitude of the resultant force on the object is A) 25 N. B) 150 N. C) 5 N. D) 0 N.

C) 5 N

Which of the following has the largest momentum relative to the Earth's surface? A) a Mack truck parked in a parking lot B) a dog running down the street C) a pickup truck speeding along a highway D) the Science building on campus E) a tightrope walker crossing Niagara Fall

C) a pickup truck speeding along a highway

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speedof the package just before it hits the ground is A) more than 30 m/s. B) zero. C) about 30 m/s. D) less than 30 m/s but larger than zero. E) More information is needed for an estimate.

C) about 30 m/s.

Hang from a pair of gym rings and the upward support forces of the rings will always A) each be equal to your weight. B) each be half your weight. C) add up to equal your weight

C) add up to equal your weight

Refraction of sound can occur in A) water. B) air. C) both air and water. D) neither air nor water.

C) both air and water.

You're driving down the highway and a bug spatters into your windshield. Which undergoes the greater change in momentum during the time of contact? A) the bug B) your car C) both the same

C) both the same

Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by A) Suzie, surprisingly. B) Arnold, of course. C) both the same, interestingly enough.

C) both the same, interestingly enough

As we become older, the frequency range of human hearing A) increases. B) remains relatively constant. C) decreases.

C) decreases

According to the impulse-momentum equation Ft = change in (mv), a person will suffer less injury falling on a wooden floor which "gives" than on a more rigid cement floor. The "F" in the above equation stands for the force exerted on the A) only the floor. B) the sum of the force on the person and the force on the floor C) either the force on the person or the force on the floor D) only the person.

C) either the force on the person or the force on the floor

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is A) more than its weight. B) less than its weight. C) equal to its weight.

C) equal to its weight

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is A) smaller. B) the same. C) greater

C) greater

An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, its acceleration A) stays the same. B) doubles. C) halves. D) quadruples. E) none of these

C) halves

In each second of fall, the distance a freely falling object will fall is A) the same, but not 5 m or 10 m. B) about 10 m. C) increasing. D) about 5 m. E) none of these

C) increasing

Resonance can be looked at as forced vibration with the A) matching of wave amplitudes. B) minimum beat frequency. C) least amount of energy input. D) maximum amount of energy input. E) matching of constructive and destructive interference.

C) least amount of energy input.

A sound wave is a A) standing wave. B) shock wave. C) longitudinal wave. D) transverse wave. E) None of the above choices are correct.

C) longitudinal wave

A decibel is a measure of a sound's A) speed. B) wavelength. C) loudness. D) frequency. E) all of these

C) loudness

A force is a vector quantity because it has both A) action and reaction counterparts. B) mass and acceleration. C) magnitude and direction.

C) mass and acceleration

Twelve seconds after starting from rest, an object falling freely will have a speed of A) 50 m/s. B) 10 m/s. C) more than 100 m/s. D) 100 m/s.

C) more than 100 m/s.

A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass? A) They have the same mass. B) the one on Earth C) the one on the moon D) not enough information to say

C) the one on the moon

Drop a rock from a 5-m height and it accelerates at 10 m/s2 and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is about A) half as much. B) twice as much. C) the same amount. D) four times as much.

C) the same amount

Double the frequency of a sound and you halve its A) speed. B) amplitude. C) wavelength. D) all of these E) none of these

C) wavelength

10-N falling object encounters 10 N of air resistance. The net force on the object is A) 10 N. B) 6 N. C) 4 N. D) 0 N. E) none of these

D) 0 N

If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, then its speed reading would increase each second by A) 30 m/s. B) 40 m/s. C) 10 m/s. D) 20 m/s. E) depends on its initial speed

D) 20 m/s.

If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about A) 3 m/s. B) 4 m/s. C) 2 m/s. D) 6 m/s.

D) 6 m/s.

At one instant an object in free fall is moving downward at 50 meters per second. One second later its speed should be about A) 55 m/s. B) 100 m/s. C) 50 m/s. D) 60 m/s. E) 25 m/s.

D) 60 m/s

If one object has twice as much mass as another object, it also has twice as much A) volume. B) acceleration due to gravity. C) velocity. D) inertia. E) all of these

D) Inertia

We are best at hearing A) both infrasonic and ultrasonic sounds. B) infrasonic sound. C) ultrasonic sound. D) None of the above choices are true.

D) None of the above choices are true

If an object of constant mass experiences a constant net force, it will have a constant A) speed. B) position. C) velocity. D) acceleration. E) more than one of the above

D) acceleration

An object in mechanical equilibrium is an object A) moving with constant velocity. B) having no acceleration. C) at rest. D) all of these

D) all of these

Which has zero acceleration? An object A) in mechanical equilibrium. B) at rest. C) moving at constant velocity. D) all of these E) none of these

D) all of these

An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the A) combined weight of the arrow and bowstring. B) air resistance against the bow. C) grip of the archer's hand on the bow. D) arrow's push against the bowstring. E) friction of the ground against the archer's feet.

D) arrow's push against the bowstring.

The two measurements necessary for calculating average speed are A) velocity and distance. B) velocity and time. C) acceleration and time. D) distance and time. E) distance and acceleration.

D) distance and time.

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is A) unchanged. B) zero. C) quadrupled. D) doubled.

D) doubled

Padded dashboards in cars are safer in an accident than nonpadded ones because an occupant hitting the dash has A) decreased impulse. B) decreased time of impact. C) increased momentum. D) increased time of impact.

D) increased time of impact

If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is A) acceleration. B) gravity. C) resistance. D) inertia.

D) inertia.

Compared to falling on a stone floor, a wine glass may not break when it falls on a carpeted floor because the A) stopping time is shorter on the carpet. B) carpeted floor provides a smaller impulse. C) carpet provides a smaller impulse and a longer time. D) stopping time is longer on the carpet.

D) stopping time is longer on the carpet.

Fourier discovered that periodic waves can be represented by A) a series of non-periodic waves. B) pulses of the same amplitude. C) a binary code. D) the summation of a series of simple sine waves.

D) the summation of a series of simple sine waves.

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be A) four times as much. B) the same. C) half as much. D) twice as much. E) none of these

D) twice as much

The source of every sound is something that is A) moving. B) a net emitter of energy. C) accelerating. D) vibrating. E) undergoing simple harmonic motion.

D) vibrating.

A large heavy truck and a small baby carriage roll down a hill. Neglecting friction, at the bottom of the hill, the baby carriage will have a greater A) acceleration. B) speed. C) momentum. D) all of these E) none of these

E) none of these