Two identical flat plates are maintained at temperatures that are greater than their surroundings $(T_s>T_{}).$ Laminar air

flows parallel over one of the plates, while laminar mercury flows over the other.

a$)$ Assuming the film temperature of both fluids is approximately room temperature, what is the Prandtl number of both

fluids?

b$)$ Qualitatively sketch the velocity and thermal boundary layers for both plates. In your sketch, also plot the velocity

and temperature distributions within the boundary layers and label the boundary layer thicknesses $(,$ and ${}_t)$ for each

plate.