Which is true about two waves who have constructive interference? A. larger amplitude than a single wave B. both waves were in phase (same side of the equilibrium line) C. amplitudes subtracted D. amplitudes added E. waves were out of phase (one above equilibrium and one below)

## Step 1<br />Constructive interference is a phenomenon that occurs when two waves meet in such a way that their crests and troughs align. This alignment results in the waves reinforcing each other, leading to a larger amplitude than either wave individually.<br /><br />## Step 2<br />Option A is correct because when two waves interfere constructively, the resulting amplitude is indeed larger than that of a single wave.<br /><br />## Step 3<br />Option B is also correct. For constructive interference to occur, the two waves must be in phase, meaning their crests and troughs align.<br /><br />## Step 4<br />Option C is incorrect. This describes destructive interference, where the amplitudes of the two waves are subtracted, resulting in a smaller amplitude.<br /><br />## Step 5<br />Option D is correct. In constructive interference, the amplitudes of the two waves are added together, resulting in a larger amplitude.<br /><br />## Step 6<br />Option E is incorrect. This describes destructive interference, where the waves are out of phase, with one wave's crest aligning with the other wave's trough.