Click on the Interference option.

Press one of the green buttons to start one faucet dripping water.

What is true about the result?

• The light colored areas represent the crests of the waves.

• The light colored areas represent the troughs of the waves.

• The dark colored areas represent the troughs of the waves.

• The dark colored areas represent the crests of the waves.

Use the Water Level tool to measure the height of the light and dark areas. What is true about these parts of the wave.

NOTE: Measure the waves nearer to the right side of the screen.

• The light areas have a higher amplitude than the dark areas.

• The light areas have a lower amplitude than the dark areas.

• The light and dark areas have the same amplitudes.

Turn on both faucets and let the simulation run a few seconds. Use the Water Level tool to measure the light areas and the dark areas.

Which of the following statements are true?

• The light areas have twice the amplitude of the original waves.

• The dark areas have twice the amplitude of the original waves.

• The light areas are areas of constructive interference.

• The dark areas are areas of constructive interference.

Next, experiment with the laser.

Recreate the image seen here.

Which part of the diagram represents the crest of the wave?

Play around with changing the frequency of the laser.

Which color has the highest frequency?

• Red

• Yellow

• Green

• Blue

• Violet

Use the measuring tape widget to estimate the wavelength of the light waves.

Which color has the largest wavelength?

• Red

• Yellow

• Green

• Blue

• Violet

Check the box marked "Screen"

Does the dark parts of the wave (trough) represent an absence of light?

• Yes

• No

Turn on the second laser and observe the resulting wave patterns.

Identify the points where constructive interference occurs.

Observe the effect of changing the frequency of the waves. What happens to the interference pattern when you increase the frequency of both waves?

• The wave pattern becomes more spaced out.

• The wave pattern becomes denser, with more crests and troughs.

• The waves stop interacting.

• The waves travel more slowly.

What happens when the amplitude of the waves is decreased?

• The light gets brighter.

• The light gets dimmer.

• The light changes color.

• The amplitude does not affect light in any way.