Energy from the sun arrives at the top of the earth’s atmosphere with an intensity of 1.30kw/m21.30⁢kw/m2. how long does it take for 1.8×109j1.8×109j to arrive on an area of 1.00m21.00⁢m2?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.