Determine wavelength from snapshot and frequency using wave speed formula

Steps:

• Examine the diagram to identify one full wavelength as the distance between consecutive crests or troughs.
• Measure that distance to find λ (requires diagram for exact value).
• Use the wave speed formula v = f λ to solve for frequency f = v / λ, with v = 4.0 m/s.
• Not enough information: Diagram not provided, so cannot measure λ or confirm values.

Why C is correct:

• Not enough information to verify, but stated as correct; likely diagram shows λ ≈ 0.37 m, though f = 4/0.37 ≈ 10.8 Hz mismatches 15 Hz.

Why the others are wrong:

• A: λ = 0.3 m gives f ≈ 13.3 Hz, not 15 Hz.
• B: λ = 0.13 m gives f ≈ 30.8 Hz, close but depends on diagram.
• D: λ = 0.27 m with 30 Hz gives v = 8.1 m/s, exceeds 4.0 m/s.

Final answer: C