Question

1. a) Name 2 properties of waves that change if the wave changes media.

b) Name a property that does NOT change when it changes media.

2. If the wavelength of a wave increases when the wave changes media, what happens to the frequency?

3. Name 2 ways to increase the energy of a wave.

4. A 2.00 m long string is vibrated 5.00 times every second to create a standing wave with 2 antinodes.
a) What is the speed of the waves creating the standing wave?
b) What is the fundamental frequency of the string?
c) What frequency will produce resonance with 3 antinodes?

Answer 1

1.) The properties of a wave are the following.
a) Amplitude - the height of the wave, measured in meters.
b) Wavelength - the distance between adjacent crests, measured in meters.
c) Period - the time it takes for one complete wave to pass a given point, measured in seconds.
d) Frequency - the number of complete waves that pass a point in one second, measured in inverse seconds, or Hertz (Hz).
e) Speed - the horizontal speed of a point on a wave as it propagates, measured in meters / second.

Among these properties, PERIOD and SPEED changes if the wave changes media. The others remain the same.

2. Speed = Wavelength * Frequency
Wavelength and Frequency are independent from each other. But you can use the given formula and assume values to check the reaction of one from another.

3. Energy of a wave is based on its amplitude. High amplitude means high energy and vice versa. To increase the energy of a wave, the amplitude must be increased. Another way of increasing the energy of a wave is using elastic medium.