cylinder made of red brass (K = 130 W/m degrees C) supports a hot reservoir at a temperature of 64o Celsius. The cylinder rests on a cold reservoir at a temperature of 17o C, has a radius of 0.70 cm, and is 11.0 cm long.
A. Find the rate of heat flow through the cylinder.
B. To reduce the heat flow, two shorter cylinders with radii of 0.610 cm and a combined length of 11.00 cm are used. The upper cylinder is made of yellow brass (K = 220 W/m degrees C), length = 2.20 cm). The lower cylinder's composition is unknown. The temperature where the two cylinders are in thermal contact is 60.81 degrees C.
C. Find the rate of heat flow through the combined cylinders.
D. Find the thermal conductivity (in W/m degrees C) of the unknown substance.