The total charge accumulated by a certain device is given as a function of time by
q(t) = 16.8 t^2 - 1.7 t^4 C.
Find:
(a) What total charge is accumulated at t=2s
(b) What is the maximum charge accumulated in the interval 0 (c) At what rate is the charge being accumulated at t=0.8s?
Use explicit methods (calculus) to determine your answers.21 s.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.