A stretched string is fixed at points 1 and 5. When it is vibrating at the second harmonic frequency, the nodes of the standing wave are at points
A) 1 and 5.
B) 1, 3, and 5.
C) 1 and 3.
D) 2 and 4.
E) 1, 2, 3, 4, and 5.

Question

A stretched string is fixed at points 1 and 5. When it is vibrating at the second harmonic frequency, the nodes of the standing wave are at points
A) 1 and 5. 
B) 1, 3, and 5. 
C) 1 and 3. 
D) 2 and 4. 
E) 1, 2, 3, 4, and 5.

Quizplus · Accepted Answer

The second harmonic frequency means that there are two antinodes and three nodes in the standing wave pattern. Since the string is fixed at points 1 and 5, the two endpoints must be nodes, and there must be one more node in between. Therefore, the nodes of the standing wave are at points 1, 3, and 5, so the correct answer is choice B.

A Stretched String Is Fixed at Points 1 and 5