Question

Freesia is trying to explain wave interference to her friend. She uses an analogy involving students pushing on a box. Which of these statements could Freesia use to explain destructive interference of waves?

a.When two students push equally on opposite sides of the box, their pushes cancel each other out.
b. When two students push equally in the same direction on a box, the effect of the pushes is greater than either separate push.
c. When one student pushes up on a box and another student pushes on the side, the box moves more quickly
d. When one student pushes down on a box and another student pushes on the side, the box is more difficult to move.

Answer 1

Freesia can explain destructive interference with an analogy where two students push on opposite sides of the box, cancelling each other's efforts, akin to wave crests and troughs cancelling out in destructive interference.

Step-by-step explanation:

To explain destructive interference of waves, Freesia could use the analogy where two students push equally on opposite sides of the box. This scenario is similar to destructive interference, which occurs when two identical waves are perfectly out of phase with each other, such as a crest meeting a trough. This results in the waves canceling each other out and producing zero amplitude, much like how the equal and opposite pushes on the box cancel each other's effects.

In the realm of sound waves, this principle can be observed when sound from two speakers creating waves that interfere can cause variations in volume; for instance, the sound may be loud in one spot and quiet in another. These volume fluctuations are evidence of waves adding partially constructively and partially destructively at different locations.

To demonstrate destructive interference using sound, a student would need to have two sound sources emitting waves that meet in such a way that a crest from one source aligns with a trough from the other, leading to cancellation of the sound. This could be achieved by precisely aligning the speakers and controlling the phase of the sounds emitted to ensure they are exact opposites at the point of interference.