Question

A satellite A of mass m is at a distance of r from the centre of the earth. Another satellite B of mass 2m is at distance of 2r from the earth’s centre. Their time periods are in the ratio of

• A. 1 : 2
• B. 1 : 16
• C. 1 : 32
• D. $1 : 2 \sqrt { 2 }$

Answer 1

Answer: (D)

$1 : 2 \sqrt { 2 }$

Answer 2

Time period does not depend upon the mass of satellite, it only depends upon the orbital radius.

According to Kepler's law $= \left( \frac { r } { 2 r } \right) ^ { 3 / 2 }$ $= \frac { 1 } { 2 \sqrt { 2 } }$