guys I really need help about this pls A bowling ball strikes a group of bowling pins at the end of a bowling lane. The total momentum of the bowling pins can only be zero if: a. The bowling pins are moving in the same direction b. The bowling pins are moving in different directions c. Some of the bowling pins are moving and some are at rest d. Some of the bowling pins are moving fast and some are moving slow

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.