Waves on a string done

Name: _________________________________ Waves on a String Virtual Lab Go to phet, simulations, HTML 5 Wave on a String . In the top left box, choose “ Oscillate .” In the top right box, choose “ No End .” In the box at the bottom, change Damping to “ None .” (Slow motion might be helpful.) 1. Is this a transverse or longitudinal wave? Transverse a. How do you know? Moving up and down 2. In which direction is the wave traveling compared to the disturbance, perpendicular or parallel? Perpendicular 3. Spend a few minutes exploring the amplitude of the wave by increasing and/or decreasing it. Describe amplitude in your own words. Amplitude is the maximum displacement of a riding wave from equilibrium i.e. the position of equilibrium is the "zero" point for amplitude. The amplitude of a wave is the distance along the wave from the equilibrium position to the position of the greatest displacement from the equilibrium position . 4. Explore how amplitude affects wavelength (distance from consecutive identical points on a wave) . Use the following settings and measure the approximate wavelength. Pause the simulation after a few waves pass and use the ruler. (Grab the ruler and drag it to measure.) Amplitude Frequency Wavelength 0.75 cm 1.60 Hz 4cm 0.90 cm 1.60 Hz 4cm 1.05 cm 1.60 Hz 4cm 1.20 cm 1.60 Hz 4cm 5. When amplitude increases, wavelength _________. a. increases b. decreases c. stays the same. 6. This means that the relationship between amplitude and wavelength is ________ a. direct b. inverse c. not related 7. When amplitude increases, energy ______ a. increases b. decreases c. stays the same. Explain why you believe this: 1

Energy is transported by waves the directed to amplitude when energy increse the amplittube of the wave increases because of fource. 8. Return the amplitude to 0.75 cm. Then, spend a few minutes exploring the frequency of the wave by increasing and/or decreasing it. Describe frequency in your own words. Frequency is a number of waves that occur repeatedly 9. Explore how frequency affects wavelength . Use the following settings and measure the approximate wavelength. Pause the simulation after a few waves pass and use the ruler. Amplitude Frequency Wavelength 0.75 cm 1.40 Hz 4.25cm 0.75 cm 1.80 Hz 3.25cm 0.75 cm 2.10 Hz 3cm 0.75 cm 2.40 Hz 2.3cm 10. When frequency increases, wavelength _______. a. increases b. decreases c. stays the same. 11. This means that the relationship between frequency and wavelength is: a. direct b. inverse c. not related 12. Return the frequency to 1.50 Hz and the amplitude to 0.75 cm. Now focus your eyes on one bead of the string. (Slow motion may help.) Describe the motion of the bead. When the red bead hits the crest the red dots come closer together but when bead is moving up/down the dots go farther away. 13. Do waves transfer matter? Use evidence from the simulation to support your answer. No, because if the waves from the simulation were waves on water if the ball was places on top of the water the waves would move the ball up and down not across. 14. Draw a transverse wave. Label the crest, trough, amplitude, and wavelength. 15. Measure the period, time for 1 complete wave cycle, using these directions. Pause the simulation. Click the timer box to access the stopwatch. Step the simulation until the grey dot is at 12 o’clock. The wave is at the highest point. Press the play button on the timer and then 2 rest

Amplitude refers to the height of a wave, frequency is the number of waves per second, wavelength is the distance between two corresponding points on a wave, and wave velocity is the speed at which the wave travels. These factors are related because the wave velocity is equal to the product of the frequency and wavelength. So, if the frequency or wavelength changes, it will affect the wave velocity 4