Question:

At what height over the earth's pole, the free fall acceleration decreases by $1%$. (Assume the radius of earth to be $6400 km$)

Updated On: May 30, 2022
  • 1.253 km
  • 64 km
  • 32 km
  • 80 km
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is C

Solution and Explanation

$g' = g( 1- \frac{2h}{R}) $ i.e. $\frac{g'}{g} = 1 - \frac{2h}{R}$ i.e. $\frac{99}{100}= 1 - \frac{2h}{6400} $ i.e. $h = \frac{3200}{100} $ = 32 km
Was this answer helpful?
0
0

Concepts Used:

Gravitation

In mechanics, the universal force of attraction acting between all matter is known as Gravity, also called gravitation, . It is the weakest known force in nature.

Newton’s Law of Gravitation

According to Newton’s law of gravitation, “Every particle in the universe attracts every other particle with a force whose magnitude is,

  • F ∝ (M1M2) . . . . (1)
  • (F ∝ 1/r2) . . . . (2)

On combining equations (1) and (2) we get,

F ∝ M1M2/r2

F = G × [M1M2]/r2 . . . . (7)

Or, f(r) = GM1M2/r2

The dimension formula of G is [M-1L3T-2].