Question

true or false
1. Destructive interference occurs when a trough meets up with another trough at a given location along the medium.
2. If a pulse with an amplitude of +5 units interferes with a pulse with an amplitude of +3 units, the resulting amplitude of the medium will be +4 units - the average of the two individual amplitudes.
3. If a pulse with an amplitude of +5 units interferes with a pulse with amplitude of -3 units, then neither constuctive nor destructive interference occurs

Answer 1

All three are false.

1. False — two troughs meeting add together (constructive interference for troughs), making a larger trough. Destructive interference happens when a crest meets a trough (opposite signs).

2. False — amplitudes add (superposition). +5 and +3 give +8, not the average.

3. False — +5 and −3 partially cancel, so destructive interference occurs (partial cancellation), leaving +2.