1. The problem statement, all variables and given/known data To better comprehend the gravitational force between the Earth and the Sun, pretend gravity is turned off and the pull replaced by the tension in a steel cable joining them. How thick would such a cable need to be? You can estimate the diameter by knowing the tensile strength of steel cable is about 5.1 * 10^8 N/m^2. 2. Relevant equations Any equations concerning gravitation/cirular motion. 3. The attempt at a solution This is my attempt at a solution, the answer key says it's wrong. F = m(4)(pi^2)(r)/t^2 d^2 = m(4)(pi^2)(r)/(t^2)(tensile strength) thickness = m(4)(pi^2)/(t^2)(tensile strength) thinkness = 465.45 m or 0.465 km Where have I gone wrong in my calculations? Can someone please steer me in the right direction. Thanks.