Question

two identical pulses are travelling along a stretched spring towards a free 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: Recall reflection at free - end

When a pulse reflects from a free - end of a spring, it reflects without inversion. So pulse A will reflect and come back in the same orientation as it went towards the free - end.

Step2: Apply principle of superposition

When two identical pulses (pulse A after reflection and pulse B) interfere, they add up constructively. Since they are identical, the amplitude of the resultant pulse will be the sum of their individual amplitudes. So the resultant pulse will be upright and larger than either of the original pulses.

Answer:

be upright and larger than pulse B