For a satellite already in perfect orbit around the earth, what would happen if: - the satellite's speed is reduced? - the satellite's mass is reduced?

Answer

Explanation:

If the satellite is in perfect orbit around the earth then gravitational pull of the earth on the satellite and moving forward satellite is in perfect balance i.e gravitational pull does not effect the orbit as the velocity of the satellite is good enough to counter the gravitational pull of the earth and inertia makes the satellite move forward with greater velocity, but when its velocity is suddenly reduced, the gravitational pull will counter on the orbiting satellite and it will crash onto the earth.

This is same as in well of death when motorist moves in circular motion inside the well with centripetal and centrifugal forces balanced, suddenly crashes on the ground when velocity of the motorist is not enough to balance forces.

the satellite's mass has no affect on its orbit around the earth rather the mass of the earth is only affecting factor .

probably not if net force is zero

vapour or gas assuming atmospheriv pressure