1. The problem statement, all variables and given/known data (a) Find the altitude above the Earth's surface where Earth's gravitational field strength would be two-thirds of its value at the surface. Assume re = 6.371 multiplied by 10^3 km. wrong check mark km (b) Find the altitude above the Earth's surface where Earth's gravitational field strength would be one-third of its value at the surface. wrong check mark km [Hint: First find the radius for each situation; then recall that the altitude is the distance from the surface to a point above the surface. Use proportional reasoning.] 2. Relevant equations F = GMm/r^2 3. The attempt at a solution I have tried it and I am either calculating wrong or setting it up wrong... or both. One problem I see with the formula is that it doesnt have the mass of the second object.. so I dont know what to do there.