$\alpha=60^{\circ}$
$60^{\circ}$ angle travelled in $1\, sec.$
$360^{\circ}$ angle travelled in $1\, sec.$ $\frac{360}{60} \times 1=6$ sec.
$(A)\;y= sin\omega t-cos\omega t$
$(B)\;y=sin^3\omega t$
$(C)\;y=5cos\left( {\frac{{3\pi }}{4} - 3\omega t} \right)$
$(D)\;y=1+\omega t+{\omega ^2}{t^2}$
