Which of the following best describes how greenhouse gases raise the average temperature of the earth? a
They allow more light to penetrate the atmosphere
b
They are naturally hotter than other, nongreenhouse gases
c
They allow in solar energy but prevent some of the infrared heat energy from leaving the atmosphere
d
They have a very high albedo, which traps heat energy

Iron reacts with sulfur to form iron sulfide. if 60 grams of iron reacts with sulfur to produce 90 grams of iron sulfide, how much sulfur has been used in the chemical reaction?

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f

An electromagnet is a device in which moving electric chargers in a coil of wire create a magnet.whats one advantage of using electromagnetic in devices