PHYS 122 SL Midterm Review #1

A mass on a spring undergoes SHM. When the mass passes through the equilibrium position, which of the following statements about it are true?

• Its acceleration is zero.

• Its speed is zero.

• Its elastic potential energy is zero.

• Its kinetic energy is a maximum.

• Its total mechanical energy is zero.

Two pendula of equal length are suspended from the ceiling.  Pendulum A has a mass of 2.5 kg and Pendulum B has a mass of 5 kg.  If Pendulum A has a period of 3 s, what will be the period of  Pendulum B?

• 1.5 s

• 1.7 s

• 3 s

• 6 s

• 9 s

Four traveling waves are described by the following equations, where all quantities are measured in SI units and y represents the displacement. Which of these waves has the same speed?

• y=0.12sin(3x+2t)

• y=0.15sin(6x-3t)

• y=0.23sin(3x+6t)

• y=-0.29sin(1.5x-t)

A position vs time graph is shown for an object undergoing simple harmonic motion.  At which point(s) is the object changing direction? Select all that apply.

• a

• b

• c

• d

• e

Suppose the damping constant b of an oscillator increases. Which of the following is true? Select all that apply.

• The total energy in the system remains conserved.

• The oscillations damp out more slowly.

• The oscillations damp out more quickly.

• The time constant τ is decreased

• The time constant τ is increased

An object is undergoing simple harmonic motion.  It takes 4.5 s for it to complete one full oscillation, which has an amplitude of 10 m.  If the object experiences a phase shift of 0 rad, what will be the object’s displacement at t = 2 s?

• 0 m

• 10 m

• -9.4 m

• -4.8 m

• 5.3 m

A wave of monochromatic light travels from glass to water. If n_glass > n_water, in which medium does the wave have a longer wavelength?

• Glass, because n_glass > n_water, and as n increases, the wave slows down, and wavelength decreases.

• Glass, because n_glass > n_water, and as n increases, the wave moves faster, and wavelength decreases.

• Water, because n_glass > n_water, and as n decreases, the speed of the wave increases, and wavelength increases.

• Water, because n_glass > n_water, and as n decreases, the speed of the wave increases, and wavelength decreases.

• They will have the same wavelength as it’s the same wave of light.

An object is undergoing simple harmonic motion.  It has a maximum velocity of v_max.  Which of the following could you do to decrease the value of v_max? Select all that apply.

• Increase the period

• Decrease the period

• Increase the amplitude

• Decrease the amplitude

 If the frequency of a sound wave is doubled, by how much will the wavelength of the wave change to ensure that it is travelling at the same speed?

•  It increases by a factor of 2

• It decreases by a factor of 4

• It is halved

• It is doubled

True or False?  k is a measure of a material’s ability to withstand changes in length due to tension or compression.

• True

• False