A. consider a perfectly spherical planet of total mass m and radius r. divide the planet into shells of mass dm and thickness dr. each shell is a different radius r from the center of the planet. write and expression for the mass dm of the shell and radius r in terms of m, r, r, and dr.
b. each shell of mass dm is "peeled" off of the remaining mass left on the planet. it takes a certain amount of energy du to remove each shell to an infinite distance away. determine the energy du required to remove the shell of mass dm that is at radius r from the planet's surface to infinity.
c. determine the total energy u required to remove all of the planet's mass to infinity.

Use the library or internet to research each planet. make a chart comparing the following: approximate surface temperature relative surface gravity compared to earth atmospheric gases water in any form: solid, gas, or liquid when you have completed your chart, use the information you have collected to answer the following questions: which is the hottest planet? which is the coldest planet? which planet's temperature is closest to that of earth? (note: water boils at 100°c/212°f. water freezes at 0°c/32°f) which planet has the greatest gravitational attraction? which planet has the least gravitational attraction? which planet's gravitational pull is closest to that of earth? do any of the planets have oxygen in their atmosphere? which planet's atmosphere most resembles that of earth? do any of the planets have flowing water? which planet's water resources (solid, gas, or liquid) might be close to the amount on earth? which planet most resembles earth in terms of all of the factors: temperature, gravity, atmosphere, and water? if earth became an uninhabitable planet, which planet do you think would be the next best to live on? explain your answer.