Question

A standing wave of frequency 5 hertz is set up on a string 2 meters long with nodes at both ends and in the center, as shown above.

The speed at which waves propagate on the string is

(A) 0.4 m/s 

(B) 2.5 m/s 

(C) 5 m/s 

(D) 10 m/s 

(E) 20 m/s

Answer 1

The correct option is: (D) 10 m/s 

Explanation:

Based on the diagram, the λ is clearly 2m. Plug into v = f λ.