A metal plate $,$ and $\{$:$c_p=880\frac{J}{k}g*K)$ with a thickness of $1$ cm is being cooled by air at $5C$ with a

convection heat transfer coefficient of $30\frac{W}{m^2}*K.$ If the initial temperature of the plate is $300C,$ determine the plate temperature

gradient at the surface after $156$ seconds of cooling. $($Round the final answer to one decimal place.$)$

The plate temperature gradient at the surface after $156$ seconds of cooling is

$\frac{K}{m}.$