SAT Math Multiple Choice Question 199: Answer and Explanation
4. Newton's law of gravitation describes the strength of the force F between two objects with masses M and m separated by a distance of r units and is defined as. F = . Which of the following gives the value of Newton's gravitational constant G, in terms of F, M, m, and r ?
- A. G = Fr2Mm
- B. G =
- C. G =
- D. G =
Correct Answer: B
B Plugging In could work on this one, but calculators aren't permitted. Since the equation is fairly simple, solving may be a better approach. Multiply both sides of the equation by r2 to get Fr2 = GMm. Divide both sides of the equation by Mm to get = G. The correct answer is (B).