PHYS 250 FINAL EXAM 2025 QUESTIONS
AND ANSWERS
Consider two children sitting on a merry-go-round, with one closer to the outer edge and one
closer to the center.
Which child has a greater angular speed? - ANS They both have the same angular speed.
Consider two equal masses M attached to the ends of massless rods, of length R, as shown in
the figure. Treat the two masses as point masses, each located at a distance R from the point
where the rods touch.
What is the moment of inertia of this system, about an axis perpendicular to the page and
passing through the point where the rods touch? - ANS 2MR^2
Consider the three objects shown in water. The wood floats while the aluminum and the steel
sink. The wooden and aluminum blocks are the same size. The aluminum and steel blocks have
equal mass and the density of steel is greater than the density of aluminum.
Which object has the greatest buoyancy force on it? - ANS The aluminum
A mass is connected to a spring and is allowed to move horizontally. The mass is at a position L
when the spring is unstretched. The mass is then moved, stretching the spring, and released
from rest. It then moves with simple harmonic motion.
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, Part (a) At the instant that the mass passes through the position where the spring is
unstretched, what can be said about its instantaneous acceleration?
Part (b) At the instant that the mass passes through the position where the spring is
unstretched, what can be said about its instantaneous speed?
Part (c) At the instant that the spring is compressed the most, what can be said about the
magnitude of its instantaneous velocity? - ANS (a) It is zero.
(b) It is maximum.
(c) It is zero.
Part (a) Which of the following are true about traveling waves? Select all that apply.
Part (b) Which of the following are true about all mechanical traveling waves? Select all that
apply. - ANS (a) Waves must have an amplitude, wavelength, and frequency., Traveling
waves are modeled as some sort of "disturbance" that travels away from its source., Traveling
waves transport energy.
(b) They must have intensity., They must have an amplitude, wavelength, and frequency., They
transfer energy., They are created by particles that are disturbed from their equilibrium
positions/state.
In a mechanical wave, the restoring force is the force that actually causes the oscillation.
In which direction does a restoring force act? - ANS opposite the direction of the
displacement from equilibrium.
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AND ANSWERS
Consider two children sitting on a merry-go-round, with one closer to the outer edge and one
closer to the center.
Which child has a greater angular speed? - ANS They both have the same angular speed.
Consider two equal masses M attached to the ends of massless rods, of length R, as shown in
the figure. Treat the two masses as point masses, each located at a distance R from the point
where the rods touch.
What is the moment of inertia of this system, about an axis perpendicular to the page and
passing through the point where the rods touch? - ANS 2MR^2
Consider the three objects shown in water. The wood floats while the aluminum and the steel
sink. The wooden and aluminum blocks are the same size. The aluminum and steel blocks have
equal mass and the density of steel is greater than the density of aluminum.
Which object has the greatest buoyancy force on it? - ANS The aluminum
A mass is connected to a spring and is allowed to move horizontally. The mass is at a position L
when the spring is unstretched. The mass is then moved, stretching the spring, and released
from rest. It then moves with simple harmonic motion.
1
Page
@COPYRIGHT SIRJOEL 2025/2026
, Part (a) At the instant that the mass passes through the position where the spring is
unstretched, what can be said about its instantaneous acceleration?
Part (b) At the instant that the mass passes through the position where the spring is
unstretched, what can be said about its instantaneous speed?
Part (c) At the instant that the spring is compressed the most, what can be said about the
magnitude of its instantaneous velocity? - ANS (a) It is zero.
(b) It is maximum.
(c) It is zero.
Part (a) Which of the following are true about traveling waves? Select all that apply.
Part (b) Which of the following are true about all mechanical traveling waves? Select all that
apply. - ANS (a) Waves must have an amplitude, wavelength, and frequency., Traveling
waves are modeled as some sort of "disturbance" that travels away from its source., Traveling
waves transport energy.
(b) They must have intensity., They must have an amplitude, wavelength, and frequency., They
transfer energy., They are created by particles that are disturbed from their equilibrium
positions/state.
In a mechanical wave, the restoring force is the force that actually causes the oscillation.
In which direction does a restoring force act? - ANS opposite the direction of the
displacement from equilibrium.
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Page
@COPYRIGHT SIRJOEL 2025/2026
