What is the reason for absence of atmosphere in some planets?

The escape speed of a projectile on the earth’s surface is 11.2 km s^-1 A body is projected out with thrice this speed. What is the speed of the body far away from the earth? Ignore the presence of the sun and other planets.

Why does the earth have an atmosphere and the moon does not?

The atmosphere is held to earth by

Which force holds the atmosphere around earth?

The clouds float in the atmosphere because of

A planet's year is 11 times the earth's year. Calculate the distance of this planet from the sun if the distance of the earth is 1.50xx10^8 km from the sun.

What is the density of SO_2 gas at 27^@C at 2 atmospheric pressure?(R = 0.08219 atm K^(-1) mol^(-1)

Can there be displacement of an object in the absence of any force acting on it?