Question

The international space station is maintained in a nearly circular orbit with a mean altitude of $330\, km$ and a maximum of $410\, km$. An astronaut is floating in the space station's cabin. The acceleration of astronaut as measured from the earth is

• A. zero
• B. nearly zero and directed towards the earth
• C. nearly $g$ and directed along the line of travel of the station
• D. nearly g and directed towards the earth

Answer 1

Answer: (D)

At height $h$, acceleration due to gravity is
$g_{h}=\frac{G M}{(R+h)^{2}}$
For $h < < R, $
$g_{h} \approx \frac{G M}{R^{2}}=g$
Direction is towards centre of earth.