A thin circular disk (diameter 0.4 m, surface emissivity ε = 0.5) has been heated up to 400 K and then left inside a chamber to cool down. The chamber surface is kept at 400 K and the air inside is maintained at 300 K. Assume that the disk is held clamped on its curved side surface by an insulator, making heat conduction and heat dissipation from the curved side surface negligible. What is the total rate of heat transfer from the disk?

Kate is working on a project in her tech education class. she plans to assemble a fan motor. which form of energy does the motor convert most of its electric energy into? a. light energy b. motion energy c. sound energy d. thermal energy

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.