Two concentric hollow spheres have radii 1 m and 2 m respectively. The space between them is filled with a material of thermal conductivity k. At time t=0, their temperatures are 273 K and 300 K respectively. Find the instantaneous heat current between the spheres.

What happens in a global convection cell

Aphysical change is a change in the size, shape,, or stafe of matter true or false

The second largest public utility in the nation is the sole provider of electricity in 32 counties of southern florida. to meet the monthly demand for electricity in these counties, which is given by the inverse demand function p = 1,200 – 4q, the utility company has set up two electric generating facilities: q1 kilowatts are produced at facility 1, and q2 kilowatts are produced at facility 2 (so q = q1 + q2). the costs of producing electricity at each facility are given by c1(q1) = 8,000 + 6q12 and c2(q2) = 6,000 + 3q22, respectively. determine the profit-maximizing amounts of electricity to produce at the two facilities, the optimal price, and the utility company’s profit