A contact resistance experiment involves pressing two slabs of different materials together, putting a known heat flux through them, and measuring the outside temperatures of each slab. Write the general expression for hc in terms of known quantities. Then calculate hc if the slabs are 2 cm thick copper and 1.5 cm thick aluminum, if q is 30,000 W/m2, and if the two temperatures are 15°C and 22.1°C.