A sinusoidal wave is sent along a string with a linear density of 2.23 g/m. As it travels, the kinetic energies of the mass elements along the string vary. Figure (a) gives the rate dK/dt at which kinetic energy passes through the string elements at a particular instant, plotted as a function of distance x along the string. Figure (b) is similar except that it gives the rate at which kinetic energy passes through a particular mass element (at a particular location), plotted as a function of time t. For both figures, the scale on the vertical (rate) axis is set by Rs = 7 W. What is the amplitude of the wave?