Comparing wave periods and amplitudes from the graph

Steps:

• Identify the period of wave X by measuring time for one full cycle; frequency f = 1/period.
• Identify the period of wave Y similarly; if it matches X's period, Y's frequency is also f.
• Measure amplitude of X as maximum displacement A from equilibrium.
• Measure amplitude of Y; if its maximum displacement is twice X's, Y's amplitude is 2A.

Why B is correct:

• Frequency equals 1/period; same cycle time means same frequency f, and amplitude doubles per graph peaks, matching definition of amplitude as max displacement.

Why the others are wrong:

• A: Period not doubled, so frequency not f/2.
• C: Cycle time not halved, so frequency not 2f.
• D: Cycle time not halved and amplitude not doubled.

Final answer: B