Question

two pulses are travelling along a stretched spring towards a fixed end as shown. when pulse a reflects and interferes with pulse b, the resultant pulse will... * 1 point be upright and larger than pulse b be upright and smaller than pulse b be inverted and larger than pulse b be inverted and smaller than pulse b have zero amplitude (complete destructive interference)

Explanation:

Step1: Understand pulse - reflection at fixed end

When a pulse reflects from a fixed end, it gets inverted. So pulse A will be inverted upon reflection.

Step2: Analyze interference

Pulse A (inverted after reflection) and pulse B will interfere. Since they are in - phase (before reflection A was upright like B), when A is inverted, they will add up constructively in terms of amplitude magnitudes. The resultant pulse will be upright (because the positive amplitudes combine) and larger than pulse B as the amplitudes of A and B add together.

Answer:

be upright and larger than pulse B