physics 2 exam 3

For a wave traveling along a string, how would you increase the wave speed without changing the physical properties of the string?

Increase the tension in the string.

If you could confine a light source to any of the shapes listed below, which would provide the greatest intensity given the same length "a"?

An equilateral triangle with side length a.

If the power of a light bulb is kept the same, what is the intensity of the light half as far away?

Four times the original intensity.

If the power of a light bulb is doubled, what is the intensity of the light twice as far away?

One half of the original intensity.

A sound source moves away from an observer. The frequency heard is

Lower than the source.

A sound source is traveling from observer A to observer B who are both at rest. The observed wavelength of the sound at B is

Less than A.

For the equations given, which describes a wave moving in the negative x-direction with a speed of 5 m/s?  t is in seconds and x is in meters.

None of these.

Without any alterations, how do sound and light generally propagate through media?

Sound and light expand like a sphere outward from their sources.

A sound source moves toward an observer. The frequency heard is

Higher than the source.

Increasing the density of a string does what to a wave on the string?

Decrease the speed.

An object is moving in simple harmonic motion from a spring. If the same object on the same spring now has an initial displacement twice that of before, what is the new maximum kinetic energy in terms of the old one?

Four times the original.

For an object on a simple pendulum moving with a small amplitude, increasing the length of the pendulum to four times its original value does what to the period?

Increase it by two.

What type of waves require a medium?

Mechanical waves.

For an object on a simple pendulum, decreasing the mass four times does what to the period of motion?

Nothing.

In what type of wave is the displacement of a point on the wave parallel to the direction of the wave's travel?

Longitudinal waves.

What type of waves are sound waves?

Longitudinal.

Doubling the amplitude of an object moving under simple harmonic motion does what to the mechanical energy?

Increase it by four.

An object is moving in simple harmonic motion from a spring. If the same object on the same spring now has an initial displacement half that of before, what is the new maximum kinetic energy in terms of the old one?

One quarter of the original.

What type of waves do not require a medium?

Electromagnetic waves.

In what type of wave is the displacement of a point on the wave perpendicular to the direction of the wave's travel?

Transverse waves.

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If at time t = 0 s the displacement from equilibrium is zero, what function describes the position of the object with respect to time?

x(t) = A sin(ωt)

For an object moving in simple harmonic motion and ignoring any effect due to gravity, when is the potential energy a minimum?

When the net force is zero.

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If the object has a minimum displacement at t = 0 s and no displacement from equilibrium at t = 2 s, what should be the function of the object's acceleration with respect to time? Do not worry about the function being positive or negative.

a(t) = B cos(ωt)

For an object moving in simple harmonic motion, when is the kinetic energy a minimum?

When the displacement is maximum.

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If the object has no displacement from equilibrium at t = 0 s and a maximum displacement at t = 2 s, what should be the function of the object's velocity with respect to time? Do not worry about the function being positive or negative.

v(t) = B cos(ωt)

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If the object has a maximum displacement at t = 0 s and no displacement from equilibrium at t = 2 s, what is the frequency of the object's motion?

f = 0.125 Hz

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If the object has a maximum displacement from equilibrium at t = 0 s and no displacement from equilibrium at t = 2 s, what should be the function of the object's velocity with respect to time? Do not worry about the function being positive or negative.

v(t) = B sin(ωt)

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If at time t = 0 s the displacement from equilibrium is a maximum, what function describes the position of the object with respect to time?

x(t) = A cos(ωt)

You are examining a graph of the position of an object moving under simple harmonic motion with respect to time. If the object has a maximum displacement at t = 0 s and no displacement from equilibrium at t = 2 s, what is the period of the object's motion?

T = 8 s