E.14.2.
Traveling Waves
Enter your responses in WebAssign E.14.2.
You'll be working with this animation. Open it now, read the description window, and play it. The animation is intended to demonstrate that the particles of the medium oscillate in place while the wave propagates through the medium. For a transverse wave, for example, the particles of the medium oscillate perpendicular to the direction of motion of the wave. It's important to understand that waves propagate energy rather than matter. Consider a stadium wave. The people are like particles of the medium. The people oscillate up and down while the wave propagates along the crowd. As you watch the animation, you can either fix your gaze on the individual particles which oscillate up and down or you can let your eyes follow the motion horizontally. For example, try watching the peak as it moves to the right. Then reverse the wave direction by entering -1.
Do the following problems. When you take measurements, give your results to 2 significant figures. If you do calculations, start with the equations in algebraic form. When you've completed the problems, enter your answers in the corresponding electronic assessment.
1. Determine the values of each of the following properties of the wave.
- amplitude
- period
- frequency
- wavelength
- speed
2. Write the equation of the wave traveling to the right. Write the equation in symbolic form. See section 14-3 of your text for guidance.
3. Now write the equation in such a way as to make it travel to the left.
4. Consider the motion of the blue point mass that oscillates along the y-axis. Write the equation describing its motion as a function of time. This will be simpler than the equation in step 2, because there's no horizontal motion. In fact, you've written equations like this before when studying oscillations in Chapter 13 (See section 13-2.) Write the equation in symbolic form.
5. Now consider the red point mass. The equation of motion of the red mass differs from that of the blue mass by a phase factor. Determine the difference in phase between the red and blue masses to the nearest tenth of a radian. You may find it helpful to display y vs. t graphs for both the blue and red point masses by clicking on Show graph. If you need to review the subject of phase, go here.