Heena Sharma, Shubhankat Vats and, Rashmi Gupta Solutions for Chapter: Gravitation, Exercise 7: Challengers*

A satellite is launched in a circular orbit of radius $R$. Another satellite is also launched in an orbit of radius $1.1 \mathrm{R}$. The period of the second satellite is larger than the first by approximately.

If earth comes closer to sun by $3/4 \mathrm{th}$ of the present distance, then the year of the earth consists of how many days?

Communication satellites move in orbits of the radius of $44400 \mathrm{km}$ around the earth. Assume that the only force acting on it is that due to the earth, then what is the acceleration of such a satellite? (Take, the mass of earth$=6\times {10}^{24}\mathrm{kg}$)

The mean radius of the Earth's orbit around the sun is $1.5\times {10}^{11} \mathrm{m}$. The mean radius of the orbit of Mercury around the sun is $6\times {10}^{10} \mathrm{m}$. The Mercury will rotate around the sun in _____.

A tank of$5 \mathrm{m}$ high is filled with water and then is filled to the top with oil of density $0.85 \mathrm{g}/{\mathrm{cm}}^3$. The pressure at the bottom of the tank, due to these liquids is _____.

A wooden block of volume $1000 {\mathrm{cm}}^3$ is suspended from a spring balance. It weighs $12 \mathrm{N}$ in air. It is suspended in water such that half of the block is below the surface of the water. The reading of the spring balance is _____.

A body is floating in water with $2/3$of its volume below the surface of the water. What is the density of the body?

A body of mass $6 \mathrm{kg}$immerses in water partially. If the body displaces $100 \mathrm{g}$ of water, then the apparent weight of the body is _____.