Question

Two identical satellites are at the heights $R$ and $7 \,R$ from the earth's surface. Then which of the following statement is incorrect :
( $R =$ Radius of the earth)

• A. Ratio of total energy of both is 5
• B. Ratio of kinetic energy of both is 4
• C. Ratio of potential energy of both 4
• D. Ratio of total energy of both is 4

Answer 1

Answer: (A)

$TE _{1}=-\frac{ GMm }{2( R + R )}=-\frac{ GMm }{4 R }$
$TE _{2}=-\frac{ GMm }{2( R +7 R )}=-\frac{ GMm }{16 R }$
$\frac{ TE _{1}}{ TE _{2}}=\frac{4}{1}$
$\frac{ KE _{1}}{ KE _{2}}=\frac{-\frac{ GMm }{4 R }}{-\frac{ GMm }{16 R }}=\frac{4}{1}$