99 Percentile Qs Bank for JEE MainPhysicsGravitation
At what depth below surface of the earth, the acceleration due to gravity will be half its value of that at 1600   km above the surface of the earth?
Options
- A4 . 8 × 10 6   m
- B3 . 19 × 10 6   m
- C1 . 59 × 10 6   m
- D5 . 5 × 10 6   m
Correct answer
A. 4 . 8 × 10 6   m
Step-by-step solution
Acceleration due to gravity at a height, g h = g 1 - 2 h R ⇒ g h = g 1 - 2 × 1600 × 10 3 6400 × 10 3 ⇒ g h = g 1 - 0 . 5 ⇒ g h = 5   m   s - 2 Given, 2 . 5 = 10 1 - d R ⇒ 1 4 = 1 - h R ⇒ 3 4 = d R ⇒ d = 3 4 × 6400 × 10 3 ⇒ h = 4 . 8 × 10 6   m