Question

1. How is the vibration of the source related to a wave's frequency?
2. How is wavelength related to frequency for waves moving at a constant speed?
3. How is energy of a wave related to its amplitude?
4. Describe two ways you could measure the wavelength of a longitudinal wave.
5. Describe how you measure the amplitude of a transverse wave.
6. If a wave's period doubles, how does the wave's frequency change?
in 8th grader terms, in short answers

Answer 1

1. The frequency is how fast the source vibrates — each vibration per second is 1 hertz (Hz). More vibrations per second = higher frequency.

2. For a fixed wave speed, wavelength = speed ÷ frequency. So if frequency goes up, wavelength goes down (and vice versa).

3. Bigger amplitude means more energy. Energy grows a lot as amplitude increases (about proportional to amplitude squared — double amplitude → about four times the energy).

4. Two ways for a longitudinal wave (like sound):
- Measure the distance between two adjacent compressions (or two rarefactions).
- Measure the wave’s speed and frequency and use wavelength = speed ÷ frequency.

5. For a transverse wave, measure the amplitude as the distance from the middle (rest) line to a crest (or to a trough) with a ruler.

6. If the period doubles, the frequency is cut in half (frequency = 1 ÷ period).