Which of the following are true for projectile motion? check all that apply
a. objects in projectile motion have only a horizontal acceleration.
b. gravity is the only force acting on an object in projectile motion.
c. projectile motion always involves motion in two dimensions.
d. for an object to be in projectile motion, air resistance must be too
small to matter.

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