Once the space shuttle is in orbit at a radius R from earth's center, what force does the seat exert on the astronaut?

Explanation

In an orbiting space shuttle, the astronaut is in free fall along with the shuttle, experiencing a gravitational force that provides the necessary centripetal force for the circular orbit. The force exerted by the seat on the astronaut is the normal force, and it is what prevents the astronaut from falling through the seat.The gravitational force acting on the astronaut is given by Fgravity =GMm/R2 The centripetal force required for the circular orbit is given by Fcentripetal =mv2 /RIn a stable orbit, Fgravity and Fcentripetal are equal. The normal force exerted by the seat on the astronaut is also equal to Fgravity , as it needs to counteract gravity to keep the astronaut in place.So, Fgravity =Mg, where g is the acceleration due to gravity at the surface of the Earth.