Question

The value of $g$ at the surface of earth is $9.8m/s^2$ then the value of ${}^{\prime }{g}^{\prime }$ at a place $480km$ above the surface of the earth will be nearly (radius of the earth is $6400km)$.

• A. $9.8m/s^2$
• B. $7.2m/s^2$
• C. $8.3m/s^2$
• D. $4.2m/s^2$

Answer 1

The correct option is C $8.3m/s^2$

Given that,

$g=9.8m/s^2$

$h=480km$

$R=6400km$

We know that,

$g^{\prime }=g(1-\frac{2h}{R})$

$g^{\prime }=9.8(1-\frac{2\times 480}{6400})$

$g^{\prime }=8.33m/s^2$

Hence, the value of g’ is $8.33m/s^2$.