Wave shifts by one wavelength in one period

Steps:

• Calculate period: T = 1/f = 1/2.0 Hz = 0.5 s.
• Time interval t = 0.5 s equals one full period T.
• Wave speed v = fλ, so distance traveled in t is v t = f λ t = λ (since f t = 1).
• Graph at t=0.5 s is identical to t=0 but shifted right by λ.

Why D is correct:

• D matches the t=0 graph shifted exactly one wavelength right, per the traveling wave displacement formula y(x,t) = y(x - v t, 0).

Why the others are wrong:

• A: Shifted left, opposite direction for positive v.
• B: No shift, ignores time passage.
• C: Partial shift (half wavelength), incorrect for full period.

Final answer: D