Cupid fires a 135-gram arrow, moving at 30 m/s, into a stationary 1 kg heart-shaped box of chocolates. The arrow emerges (the arrow does not get embedded (or stuck) in the box)
with half of its original speed. Find the change in the kinetic energy of the system before
and after the collision.

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Iwill give brainliest if you answer right : )

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)