The height at which the acceleration due to gravity becomes $$\frac{g}{16}$$ (where, g = acceleration due to gravity on the surface of the earth) in terms of R is, if R is the radius of earth.

The escape velocity of a projectile on the earth's surface is 11.2 km/s. A body is projected out with thrice this speed. The speed of the body far away from the earth will be

Kepler's second law of planetary motion corresponds to

A constant potential energy of a satellite is given as

$$\mathrm{PE}=r(\mathrm{KE})$$

whee, PE = potential energy

and KE = kinetic energy.

The value of $$r$$ will be