# Waves, frequency, and power

## Homework Statement

Two identical but separate strings, with the same tension, carry sinusoidal waves with the same amplitude. Wave A has a frequency that is twice that of wave B and transmits energy at a rate that is ____ that of wave B.
A) half
B) twice
C) one fourth
D) four times
E) eight times

## Homework Equations

$$P = \frac{1}{2}\mu\omega^{2}A^{2}v$$
$$v = \lambda$$$$f$$

## The Attempt at a Solution

$$V_{B} = \lambda$$$$f_{B}$$
$$V_{A} = \lambda$$$$(2f_{B})$$ = $$2V_{B}$$
$$P_{B} = \frac{1}{2}\mu\omega^{2}A^{2}v_{B}$$
$$P_{A} = \frac{1}{2}\mu\omega^{2}A^{2}2v_{B}$$ = $$2P_{B}$$

However, the answer key says D. What did I do wrong?