The problem is: The sun is 1.5x10^11 meters from the earth. Energy from the sun is received at the earth's surface at the rate of 1.4 kilowatts per square meter. I'm trying to find two answers: 1. This energy flux from the Sun falls on a pond of water 100 square meters in area and 0.1 meter in depth. Assume all of this energy heats the water. Find the average temp. rise of the pond after 10^3 seconds 2. Determine the rate in kilograms per second at which the sun's mass is being converted to energy. For 1, energy flux is Iota=power/area, power=work/time, For 2, the SA of a sphere is 4pir^2, E=mc^2 So far I have p/1000 for energy flux and power=w/1000. I'm stuck on what to do next, but since the question gives you the distance between the earth and sun, would w=fd help you find the solution? This question seems unusual compared to ones I've done in the past.