Final answer:
To increase the speed of a wave on a string, use a lighter string and stretch the string tighter to increase the tension. Moving the hand faster or with greater distance affects frequency and amplitude, not wave speed, and a heavier string or looser tension decreases wave speed.
Step-by-step explanation:
To increase the speed of a wave down a string, you can take several actions. Here are the choices from the question and their impact on the wave speed:
- A. Move your hand up and down more quickly as you generate the wave - This will increase the frequency of the waves but not their speed along the string.
- B. Move your hand up and down a greater distance as you generate the wave - This will increase the amplitude of the waves but not the speed of the wave along the string.
- C. Use a heavier string of the same length under the same tension - A heavier string would decrease the wave speed because wave speed is inversely related to the square root of the linear mass density of the string.
- D. Use a lighter string of the same length under the same tension - This would increase the wave speed because the lighter the string, the lower its linear mass density, which results in a higher wave speed.
- E. Stretch the string tighter to increase the tension - Increasing tension will increase the wave speed according to the wave speed equation, where wave speed is directly proportional to the square root of the tension.
- F. Loosen the string to decrease the tension - Decreasing the tension will reduce the wave speed along the string.
So, the correct actions that would increase the speed of the wave down the string are D. Using a lighter string and E. Stretching the string tighter to increase the tension.