Question

7 whats an easy way to create an interference pattern of waves?
a shine a light onto a black surface; the dark color will interfere with the transmission of light
b broadcast radio waves from a tower; water particles in the atmosphere will interfere with the transmission
c play music through a board with one hole in it; the board will interfere with the sound waves
d toss two pebbles into the water close to each other; the waves from each pebble will interfere with the other

Explanation:

To create a wave interference pattern, two coherent wave sources are needed. Option D involves tossing two pebbles into water close together. Each pebble creates circular water waves, and these waves (from two sources) interfere with each other, forming an interference pattern. Option A is about light absorption by a black surface (not interference). Option B describes radio wave interference from atmospheric water, but it's not a method to create an interference pattern. Option C is about sound wave diffraction (through one hole) or absorption, not interference (which needs two wave sources).

Answer:

D. Toss two pebbles into the water close to each other; the waves from each pebble will interfere with the other