In order for work to be done, what three things are necessary?

Agas contained within a piston-cylinder assembly undergoes three processes in series: process 12: compression with pv= constant from 1 bar and 1 liter to 4 bar. process 23: constant pressure expansion to 1 liter. process 31: constant volume calculate the pressure and volume at each state, and sketch the processes on a p-vdiagram labeled with pressure and volume values at each numbered stat

What quantity do units represent in value

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?