In an isochoric process, the internal (thermal) energy of a gas decreases by 50 j. how much work is done by the gas during this process

The amount of work done by the gas during this process is: 0
The isochoric process is a thermodynamic process in which the volume will always remain contant.

work could be calculated = P x dV

since dV = 0, there wore the amount of work done by this process is also 0

If there was no gravity then their would be no downword force on the football to have it return the the grownd, and if there was no friction (mainly air friction) then there would be no opposing force the stop the ball from moving through the air allowing the ball to travle ∞.