A commercial soda$-$lime silicate melt has a crystal melting temperature $($liquidus temperature$)$ of $1010$oC$,$ a TTT nose temperature of $955$oC$,$ a glass transition temperature of $550$oC$,$ and a TTT nose time of $45$ seconds. What is the critical cooling rate for this melt to form a glass? Answers are in oC$/$second$.$