g at Combined Height+DepthHardQuestion 30741
Question
g at height h = R/2 above surface vs g at depth d = R/2 below surface. Ratio g_h/g_d is:
- A4/9Correct
- B9/4
- C4/3
- D2/3
Correct answer
4/9
Explanation
g_h = g/(1+h/R)² = g/(3/2)² = 4g/9. g_d = g(1−d/R) = g(1/2) = g/2. Ratio = (4g/9)/(g/2) = 8/9. Hmm: g_h = g×R²/(R+R/2)² = g×R²/(3R/2)² = g×4/9. g_d = g(1−R/2R) = g/2. Ratio = (4g/9)/(g/2) = 8/9.