Answer:
The system can be described by a convolution
Explanation:
Thinking process:
If we consider a discrete input to a linear time-invariant system, then the system will be periodic with respect to the period, say N. This therefore, means that the output must also be periodic. The proof is as follows:
The LTI system can be written for the system where:
y (n+N) = ∑
= ∑
From the proof, it turns out that y(y + N) = y(n) for any value of n, then the output will be the periodic with the period N.
The all purpose one will work or you could use type C I believe.
Reflection helps designers to learn from their experiences, to integrate and co-ordinate different aspects of a design situation, to judge the progress of the design process, to evaluate interactions with the design context, and to plan suitable future design activities.
Answer:
123.9 Btu
Explanation:
The energy balance on the air is:
∆E = E2 − E1 = ∆KE + ∆PE + ∆U = Q + W
ignore ∆KE and ∆PE,
W = ∆U − Q = m(u2 − u1) − Q; (u2 − u1 = 51.94 Btu/lb)
ideal gas properties is attached
W = (2 lb)(143.98 − 92.04) Btu/lb − (− 20 Btu) = 123.9 Btu
u2 − u1 ≈ cv(T2 − T1) = (0.173 Btu/lb°R)(840 − 540)
°R = 51.9 Btu/lb
