A water slurry containing coal particles $(S G=1.35)$ is pumped into the bottom of a large tank (10 ft diameter, $6 \mathrm{ft} \mathrm{high}$ ), at a rate of $500 \mathrm{gal} / \mathrm{h}$, and overflows at the top. What is the largest coal particle that will be carried over in the overflow? If the flow rate is increased to $5000 \mathrm{gal} / \mathrm{h}$, what size particles would you expect in the overflow? The slurry properties can be taken to be the same as for water.