Question

If the acceleration due to gravity, g, is 10 $m/s^2$ at the surface of the earth (radius 6400 km), then at a height of 1600 km the value of g will be ( in $m/s^2$)

• A. 6.4
• B. 5
• C. 7.5
• D. 2.5

Answer 1

The correct option is B 5

Let $g_e=10m/s$

$R_e=6400m$

$g^{\prime }=?$

hence by formula

$g^{\prime }-g_e=\frac{1}{2}\times \frac{h}{R_e}$

thus g=-4.9 m\s