A cube with each side equal to $5cm$ was taken out of a refrigerator. It has been stored in this

refrigerator at $5C$ for a long time. Then, this cube is dipped in $85C$ hot water.

We know that: the $=950k\frac{g}{m^3},k=0\mathrm{.}5\frac{W}{m*K}$ and $C_P=3700\frac{J}{kg*K}.$ Also, the heat

transfer coefficient $h=650\frac{W}{m^2*K}.$

a$)$ What do these properties $(,k,C_P)$ refer to$?$

b$)$ What does the $h$ mean in this problem? Please describe it clearly.

c$)$ What is the Biot number in this problem?

d$)$ How long does it take for the center of the cube to reach $50C?($use Appendix $F$ if needed$)$