The figure shows two waves traveling in the positive-x direction. The amplitude of the resultant wave is closest to
A) 2.0 mm.
B) 1.8 mm.
C) 1.4 mm.
D) 1.0 mm.
E) zero.

Question

The figure shows two waves traveling in the positive-x direction. The amplitude of the resultant wave is closest to
A) 2.0 mm. 
B) 1.8 mm. 
C) 1.4 mm. 
D) 1.0 mm. 
E) zero.

Quizplus · Accepted Answer

The amplitude of the resultant wave can be calculated by adding the amplitudes of the two waves at each point along the x-axis. At x = 0, the amplitude is 2 mm (1 mm + 1 mm). At x = λ/2, the amplitude is 0 (1 mm - 1 mm). At x = λ, the amplitude is 2 mm again (1 mm + 1 mm). Therefore, the amplitude of the resultant wave varies between 0 and 2 mm, but the closest value to this range is 1.0 mm (choice D).

The Figure Shows Two Waves Traveling in the Positive-X Direction