The weight of an object varies inversely with the square of its distance from the center of the earth. Assume that the radius of the earth is 3960 miles. If an astronaut weighs 180 pounds on the surface of the earth, what does that astronaut weigh when traveling 300 miles above the surface of the earth?
I developed the equation W = k/(r^2) from the given information, where W = weight of an object, r = radius distance from the center of the earth. After doing the math, I got nowhere near what the answer should be.
I then tried setting up the following proportion:
180 pounds/x pounds = 3960 miles/300 miles
After solving for x, I got 13.64 pounds, which is wrong.
The correct answer is 1.56 pounds.
How do I get that answer? What is the correct equation?