. A long string carries a wave; a 6-m segment of the string contains four complete wavelengths and has a mass of 180 g. The string vibrates sinusoidal with a frequency of 50 Hz and a peak-to-valley displacement of 15 cm. (The “peak-to- valley” distance is the vertical distance from the farthest positive position to the farthest negative position.) (a) Write the function that describes this wave traveling in the positive x direction. (b) Determine the power being supplied to the string. (c) What is the energy contained in each cycle of the wave?