An astronaut who weighs $162$ pounds on the surface of the earth is orbiting the earth at a height above the surface of the earth of two earth radii ($h = 2R$ where R is the radius of the earth.)

How much does this astronaut weigh while in orbit at this height (With how much force is the earth pulling on him while he is in orbit at this height?)

Kepler's first law provides information about-

Ratio of time period of satellites orbiting around earth at a distance of about 9r and 4r from earth surface is : ( where r is the radius of earth)

কেপলারের পর্যায়কালের সূত্র —

When Johannes Kepler developed his laws (or the movement of planetary bodies), one of the law' stated that the orbits of the planets about the sun are