Question

The gravitational force on a body of mass $5kg$ at the surface of the earth is $50N$. If earth is a perfect sphere, the gravitational force on a satellite of mass $200kg$ in a circuit orbit of radius same as diameter of the earth is.

• A. $200N$
• B. $400N$
• C. $500N$
• D. $800N$

Answer 1

Answer: (C)

$500N$

Given that body of mass $=5kg$

Weight $=w=50N$

$w=mg$

$50=5g$

$g=10m/s^2$

$(D=2R)$ $(h=R)$

$\Rightarrow g^{\prime }=\frac{10}{{(1+\frac{R}{R})}^2}=\frac{10}{4}$

$g^{\prime }=2.rm/s^2$

$w^{\prime }=m^{\prime }{g}^{\prime }$

$=200\times 2.5$ (Lets, weight on satellite $=w^{\prime }{m}^{\prime }=200kg$)

$=500N$

Option (C) is correct.