Question

The value of ${}^{\prime }{g}^{\prime }$ at a depth of $80km$ will be (Radius of earth $=6400km$ and value of ${}^{\prime }{g}^{\prime }$ on the surface of earth is $10m/s^2$)

• A. $990cm/s^2$
• B. $980cm/s^2$
• C. $970cm/s^2$
• D. $1000cm/s^2$

Answer 1

The correct option is C $970cm/s^2$

Let $g^{\prime }/ge$ the acceleration due to gravity in mins

Then $g^{\prime }=g(1\times \frac{d}{R})=9.8(1-\frac{640}{6400}\times {10}^3)$

$=9.8\times 0.9999m/s^2$

$=9.799m/s^2$