If the coefficient of static friction between the crate and ramp in exercise 61 equals $\mu_{s},$ physics tells us that the crate will slide down the ramp if the component of $\mathbf{w}$ along $\mathbf{v}$ is greater than the product of $\mu_{s}$ and the component of $\mathbf{w}$ along $\mathbf{n}$. Show that this occurs if the angle $\theta$ is steep enough that $\theta>\tan ^{-1} \mu_{s}$