Physics Final Exam
Which of the following wavelengths is common to a 10-cm tube open at both ends and a 15-cm tube open at one end and closed at the other?
20 cm
An object of mass m is attached to a horizontal spring, stretched to a displacement A from equilibrium and released, undergoing harmonic oscillations on a frictionless surface with period T0. The experiment is then repeated with a mass of 4m. Choose the new period of oscillation.
2T0
Which of the following statements are true?
Answer: (i) is true, but (ii) is false
Suppose that a grandfather clock is calibrated correctly at sea level and is then brought up to the top of a tall mountain. What would need to be done to calibrate the clock at the top of the mountain?
The bob of the pendulum should be slid slightly up the rod.
Which of the following could be associated with a temperature increase for a fixed amount of gas?
an increase in the pressure at constant volume
Which of the following frequencies are higher harmonics of a string with fundamental frequency of 150 Hz?
300 H z & 600 H z
Two objects made from the same material have different masses and different initial temperatures as shown. If the bodies are placed in thermal contact, the final equilibrium temperature is most nearly:
47°C
A block on the end of a horizontal spring is pulled from equilibrium at x = 0 to x = A and released. Through what total distance does it travel in one full cycle of its motion?
4A
To have your coffee be as hot as possible when you drink it later, when should you add room temperature cream?
As soon as the coffee is served`
Consider the two systems below, labeled A and B. Which gas has the higher pressure?
B & Neither; the pressures are the same.
Calculate the slopes for the A, C, and E portions of the figure. Rank the slopes from least to greatest.
C, A, E
Body A has a higher temperature than body B. Which of the following statements is true?
If placed in contact with each other, energy will flow from body A to body B.
Consider an amount of water freshly melted from snow in a pan and that the water has a temperature of 1°C. What will happen to the water as its temperature is increased to 3°C?
It will contract slightly (its volume will decrease).
A metallic key ring of 1.00 cm diameter is placed in a fire and heated up. What would you expect would happen to the inside diameter of the ring as it heats up?
It will expand as the metallic portion expands
Two identical springs are attached to two identical masses. Both are resting on a frictionless horizontal surface. One of the springs is displaced a distance d from its equilibrium position, while the other is displaced a distance 2d. If both masses are released at the same instant, which of the springs, A or B, returns to its unstretched length first?
It's a tie.
If the wavelength of sound is increased by a factor of 3, what happens to its speed and frequency?
Its frequency decreases by a factor of 3, but its speed stays the same.
Temperature is a measure of...
None of the above.
The intensity of a sound wave is a measure of:
None of the above.
Two sound waves can interfere:
None of the above.
Two identical thermodynamic systems, one at T1 and the other at T2, are placed in thermal contact. When they reach thermal equilibrium, what is true about the final temperature?
Tfinal = ½(T1 + T2)
You have 1 k g of liquid water and 1 k g of steam. If you want to increase the temperature of both of them by 10°C, which would require more added energy?
The Water
Suppose you're on a hot air balloon ride, carrying a buzzer that emits a sound of frequency f. If you accidentally drop the buzzer over the side while the balloon is rising at constant speed, what can you conclude about the sound you hear as the buzzer falls towards the ground?
The frequency decreases and the intensity decreases.
Let's say that a gas decreases in temperature, but that its volume remains constant during this process. What happens to its internal energy in this case?
The internal energy decreases.
If a meter stick is metallic and is used for measuring lengths at room temperature, what will be the effect of using the same meter stick for measuring lengths outside on a snowy day?
The lengths measured outside would be slightly greater than those measured inside.
Which of the following is true for an oscillating spring?
The potential energy is greatest when the spring is the most compressed and the most extended.
A ringing alarm clock is placed in a bell jar, which is then sealed, and the air is pumped out of it. Which effect will most likely occur?
The sound of the ringing alarm clock will get softer as the air is pumped out.
Which of the following phrases best describes heat?
The total energy flowing between two bodies at different temperatures.
Two spheres are made of the same metal and have the same radius, but one is hollow and the other is solid. The spheres are taken through the same temperature increase. Which sphere expands more?
They expand by the same amount.
Why doesn't the melting of ocean-based ice raise as much concern and the melting of land-based ice?
Unlike land-based ice, ocean-based ice already displaces water, so when it melts ocean levels won't change much.
Is it possible to add energy to an isolated material and not have the material's temperature change?
Yes, in some cases a material's temperature will change when energy is added to the material. In other cases, the material's temperature will not change when energy is added
Which of these represents an example of simple harmonic motion?
a marble rolling back and forth in a concave bowl & a tree branch vibrating
When an object moving in simple harmonic motion is at its maximum displacement from equilibrium, which of the following is at a maximum?
acceleration
For which of the following will the phenomenon of wave interference apply? (Choose the best answer.)
all of these: square-shaped pulses, sinusoidal pulses, triangular pulses
A simple pendulum is suspended from the ceiling of a stationary elevator, and the period is measured. If the accelerates upward, the period
decreases
As an airplane flying with constant velocity moves from a cold air mass into a warm air mass, the Mach number
decreases
An object of mass m is attached to a horizontal spring, stretched to a displacement A from equilibrium and released, undergoing harmonic oscillations on a frictionless surface. The experiment is then repeated with a mass of 4m. Compared to the original total mechanical energy, the subsequent total mechanical energy of the object with mass 4m is
equal
A pipe open at both ends resonates at a fundamental frequency fopen. When one end is covered and the pipe is again made to resonate, the fundamental frequency is fclosed. Which of the following expressions describes how these two resonant frequencies compare?
fclosed = 1/2 fopen
Two objects with different sizes, masses, and temperatures are placed in thermal contact. Choose the best answer. Energy travels
from the object at higher temperature to the object at lower temperature
If you are asked to make a very sensitive glass thermometer, which of the following working fluids would you choose?
gasoline
If you quickly plunge a room-temperature mercury thermometer into very hot water, the mercury level will
go down briefly before reaching a final reading.
The period of a simple pendulum is measured to be T on the Earth. If the same pendulum were set in motion on the Moon, would its period be
greater than T
One container is filled with argon gas and another with helium gas. Both containers are at the same temperature. Which molecules have the higher r m s speed?
helium
Raising the temperature of air will
increase the speed of sound in the air.
Consider a rope hung from the top of a tall ceiling to the ground. Someone sets up waves from the bottom of the rope and watches as they propagate up the rope. The wave's speed along the vertical rope will
increase with vertical position up the rope.
Balboa Park in San Diego has an outdoor organ. When the air temperature increases, the fundamental frequency of one of the organ pipes (the thermal expansion of the pipe is negligible)
increases
Which of the following actions will increase the speed of sound in air?
increasing the air temperature
Suppose you have 1 k g each of iron, glass, and water, and all three samples are at 10°C. Rank them from least to greatest amount of energy transferred by heat if enough energy is transferred so that each increases in temperature by 20°C.
iron, glass, water
Let's say that you are spinning a fixed-frequency buzzer attached to a string in a circular path around you at a constant speed. The frequency that you hear as you spin the buzzer
is the same as the frequency of the buzzer.
The energy that flows in a sound wave is:
kinetic energy only & both kinetic and potential energy.
Sound waves may be best described as being
longitudinal waves.
You are tuning a guitar by comparing the sound of the string with that of a standard tuning fork. You notice a beat frequency of 5 Hz when both sounds are present. You tighten the guitar string and the beat frequency rises steadily to 8 Hz. To tune the string exactly to the tuning fork, you should
loosen the string
When a standing wave occurs on a string,
many points along the string move up and down, some move more than others, and some are stationary.
You measure the temperature of two objects and one of them is warmer than the other. From this you can conclude
none of these statements.
If the amplitude of a system moving in simple harmonic motion is doubled, which of the following quantities doesn't change?
period
For a simple harmonic oscillator, which of the following pairs of vector quantities can't both point in the same direction? (The position vector is the displacement from equilibrium.)
position and acceleration
A simple pendulum is suspended from the ceiling of a stationary elevator, and the period is measured. If the elevator moves with constant velocity, the period
remains the same
A pendulum clock depends on the period of a pendulum to keep correct time. Suppose a pendulum clock is keeping correct time and then Dennis the Menace slides the bob of the pendulum downward on the oscillating rod. The clock then runs
slow
The phenomenon of interference is the result of:
superposition
The use of the term "sound waves" in air is meant to describe:
the pressure variations in air
A small, hot object makes thermal contact with a more massive, equally hot object. Consequently,
there will be zero net flow of energy.
Suppose you have 1 k g each of iron, glass, and water, and all three samples are at 10°C. Rank the samples from lowest to highest temperature after 100 J of energy is added to each by heat.
water, glass, iron
For which of the following would it be most advisable to utilize a system that is damped?
within shock absorbers
Three systems are constructed from identical springs and masses as shown. Which statement is true regarding the frequencies of these systems?
ω1 = ω2 = ω3
