A planet is from the Sun and has a speed of

PHYSICS · Subjective · CBSE · Physics · Gravitation · Gravitation

Problem

A planet is

1.5\times10^{11}\,\text{m}

from the Sun and has a speed of

3.0\times10^{4}\,\text{m\,s}^{-1}

. (i) When it later reaches a distance of

2.0\times10^{11}\,\text{m}

, calculate its speed. (ii) If the line joining the planet and the Sun sweeps out an area of

5.0\times10^{21}\,\text{m}^2

while moving between these two positions, determine the time taken for this part of the journey.