Acar starts from rest and is subjected to a constant
acceleration of a=15ft/s^2 for 0< =t< 10s . the brake is then
applied , which causes a deceleration at the rate shown until the
car stops. determine the t1when the car stops.

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?