Final answer:
To decrease the wavelength of a wave in a string, the student could shake their hand with greater frequency or increase the tension in the string by stepping back. Greater amplitude of shaking does not affect wavelength.
Step-by-step explanation:
The student is studying wave properties in a physics context by shaking a string in a rhythmic manner. To decrease the wavelength within the rope, the following actions could be taken:
- The student could shake their hand back and forth with greater frequency. Increasing the frequency of the hand's movement will result in more waves being produced along the rope in a given amount of time, which decreases the wavelength.
- The student could increase the tension within the rope by stepping backwards from the board. Increased tension in the string will result in waves moving faster, which for a given frequency, reduces the wavelength.
It's important to note that shaking the hand with greater amplitude does not affect the wavelength but affects the energy and amplitude of the waves on the string.