Download Physics 1260 Test 1: Questions and Answers on Simple Harmonic Motion, Waves, and Sound and more Exams Physics in PDF only on Docsity!
PHYS 1260 TEST 1 2025 QUESTIONS AND CORRECT
ANSWERS
A person's heart rate is given in beats per minute.
Is this a period or a frequency?
frequency
A young girl and her mother are swinging on a swing set
Who, if either, has the longer period of oscillation? Suppose that both of them can be treated as simple pendulums with the same length and simple harmonic motion.
Mother and daughter will oscillate with the same period since the period does not depend on the object's mass.
The type of function that describes simple harmonic motion is _______.
sinusoidal
When you displace an object from its equilibrium position and the force pushing it back toward equilibrium is _____, the resulting motion is simple harmonic motion.
linear
A mass is undergoing simple harmonic motion. When its displacement is 0, it is at its equilibrium position. At that moment, its speed is _______ and its acceleration is _______.
maximum; 0
Which of the following is a longitudinal wave?
sound wave
Changing which of the following quantities will affect how quickly a wave travels along a string (assuming all else is held constant)?
Linear density of the string
Tension in the string
A wave transfers _______ as it moves away from the source.
energy
A lens collects light and focuses it into a small spot. This increases the ________ of the light wave.
energy
As you run toward a source of sound, you perceive the frequency of that sound to ________.
increase
A guitarist finds that the pitch of one of her strings is slightly flat - the frequency is a bit too low.
Should she increase or decrease the tension of the string? Explain.
The frequency of a vibrating string is determined by fn=(n/(2L)) sqrtT/μ. So if the tension in the string increases, the rate at which it vibrates (the frequency) will also increase.
When two waves overlap, the displacement of the medium is the sum of the displacements of the two individual waves. This is the principle of __________.
superposition
A point on a standing wave that is always stationary is a(n) _____.
node
You can decrease the frequency of a standing wave on a string by __________.
making the string longer
using a thicker string
decreasing the tension
We describe sound waves in terms of pressure. Given this, for a standing wave in a tube open at each end, the open ends of the tube are __________.
nodes
- At which time or times shown is the potential energy a maximum?
- ACE
2.ACE
3.BD
Four different masses are hung from four identical springs with an unstretched length of 10 cm, causing the springs to stretch as noted in the following diagram:
Now, each mass is pulled down by an additional 1 cm and released, so that it oscillates up and down. Which of the oscillating systems has the highest frequency?
C (spring 25 cm, 100 g)
Four 100-g masses are hung from four springs, each with an unstretched length of 10 cm. The four springs stretch as noted in the following diagram:
Now, each of the masses is lifted a small distance, released, and allowed to oscillate. Which mass oscillates with the highest frequency?
Mass A
A pendulum is pulled to the side and released. The mass swings to the right as shown. The diagram shows positions for half of a complete oscillation.
- At which point or points is the speed the highest?
- At which point or points is the acceleration the greatest?
- At which point or points is the restoring force the greatest?
- C
- A, E
- A, E
A mass on the end of a string is pulled to the side and released.
- At which time or times shown is the acceleration zero?
- At which time or times shown is the kinetic energy a maximum?
- At which time or times shown is the potential energy a maximum?
1.BD
2.BD
3.ACE
For a wave pulse on a string to travel twice as fast, the string tension must be
Decreased to one fourth its initial value.
A wave bounces back and forth on a guitar string; this is responsible for making the sound of the guitar. As the temperature of the string rises, the tension decreases. This..... the speed of the wave on the string.
Decreases
A speaker emits a 400-Hz tone. The air temperature increases. This Fill in the blank the wavelength of the sound.
Increases
In the figure below the charge in the middle is Q = 5 nC. For what charge q1 will charge q2 be in static equilibrium?
-20 nC
How much work was required to bring a charge Q= -1 nC into the position shown?
227 nJ
Suppose a -1nC charged bead with a mass of 1 microgram is fired into a parallel plate capacitor at a speed of 1.4 m/s. There is a 1000V potential difference between the plates. How close to the upper (-) plate will the bead get before falling back down to the lower (+) plate?
1 cm
In the figure Q = +2 nC and all other quantities are exact. What is the magnitude of the force on the charge Q?
6.2x10^-4 N
A thin, flexible rod of length L = 10 cm carries charge Q = 100 nC uniformly along its length. The rod is then bent into a semicircle, as shown in the figure. What is the magnitude of the electric potential at the center?
9000π volts
mass of 2M and a charge of Q/2. The beads are a distance D apart before being released. How fast will each bead be moving if you examine them long after being released?
v2 = sqrt(KQ^2/2MD) and v1 = sqrt(2KQ^2/MD)
Suppose you put a +1nC charge at each corner of a cube. The electric field in the center of the cube will be zero, but the electric potential in the center will NOT be zero.
True
Which of the following statements is true about the charge configuration shown?
The electric potential at every point on the z-axis between point P and point O is zero, but the electric field is NOT zero along the z-axis between point P and point O.
How many electrons are there in 1 mole of electrically neutral 12C atoms?
About 3.6x10^24 electrons
Suppose two charged beads are released from rest out in space. One (bead #1) has a mass of M and a charge of Q. The other (bead #2) has a mass of 2M and a charge of Q/2. The beads are a distance D apart before being released. Which of the following statements is true?
The heavier bead will accelerate at half the rate of the lighter bead, and it's speed will always be half the speed of the lighter bead.
An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown below will the electron follow?
Trajectory Z
What is the electric potential 1 m away from a +1 nC charge?
9 V
A negatively charged rubber ballon will attract a positively charged plastic rod.
True
A charged particle experiences two electrostatic forces (due to other, nearby charged particles). The force vectors are perpendicular to each other. How can you find the magnitude of the net force.
Use the pythagorean theorem
Which of the following is an impossible amount of charge?
+14e
+e
+1.5e
-2e
What is the mass number of an atom?
It is the total number of protons and neutrons in the nucleus.
Which can be produced in a pair production?
an electron and a positron
In the radioactive decay of a nucleus, what happens to the total charge?
The initial nucleus has the same amount of charge as the resulting decay products.
If a negatively charged conductor is connected to ground, what happens to the conductor?
becomes neutral
Which describes an electric field?
It is a number field
It is a scalar field
It is a vector field
What is the direction of the electric field vectors set up by a positively charged particle?
radially away from the particle
