How will you ‘weigh the sun’, that is estimate its mass? The mean orbital radius of the earth around the sun is `1.5 xx 10^8 km`.

A planet is revolving round the sun in elliptical orbit. The maximum and minimum distances of the planet from the sun are 2 xx 10^2 m and 2 xx 10^10 m respectively. The speed of the planet when it is nearest to sun is 2 xx 10^15 ms^-1 What is the speed when it is farthest to the sun?

Find the mass of earth (Given the radius of earth R= 6.4 xx 10^6 m) .

Calculate the mass of the earth. Given radius of the earth =6.4xx10^-6 m and g = 9.8 m//s^2

Io, one of the satellites of Jupiter, has an orbital period of 1.769 days and the radius of the orbit is 4.22 xx 10^8 m . Show that the mass of Jupiter is about one-thousandth that of the sun.

In accordance with the Bohr's model, find the quantum number that characterises the earth's revolution around the sun in an orbit of radius 1.5 xx 10^11 m with orbital speed 3 xx 10^4 m/s . (Mass of earth = 6.0 xx 10^24 kg .)

State whether the following statements are always true, always false or ambigous. Justify your answer : The distance from the Earth to the Sun is approximately 1.5 xx 10^8 km.

What will be the corresponding expression for the energy needed to completely diassemble the planet earth against the gravitational pull amongst its constituent particles? Assume the earth to be a sphere of uniform mass density. calculate the energy, given that the product of the mass and the radius of the earth to be 2.5xx10^(31)kg-m

A satellite orbits the earth at a height of 400 km above the surface. How much energy must be expended to rocket the satellite out of the earth’s gravitational influence? Mass of the satellite = 200 kg, mass of the earth = 6.0xxl0^24 kg , radius of the earth = 6.4 xx 10^6 m , G = 6.67 xx 10^11 N m^2kg^2 .