Two waves are generated on a string of length $3.0 \mathrm{~m}$ to produce a three-loop standing wave with an amplitude of $1.0 \mathrm{~cm}$. The wave speed is $100 \mathrm{~m} / \mathrm{s}$. Let the cquation for one of the waves be of the form $y(x, t)=y_{m} \sin (k x+\omega t) .$ In the equation for the other wave, what are (a) $y_{m},$ (b) $k,$ (c) $\omega$, and (d) the sign in front of $\omega ?$