Modeling Discrete Time Systems

In addition to modeling (refer to chapter 3.8.2 in the textbook Page 253) that shows the conversion from a time-domain RC filter to a discrete-time signal, and transforming, let us discuss the following:

1. In the given RC circuit which is in the .JPG file above, what is Vo(t)? The Laplace transformed voltage equation would be Vo(s) = Vi(s) x [(1/(sC)) / (R + 1/(sC))] where Vi(s) = 2/s, 2 V step. Then solve it for Vo(t). 

2. To convert from the analog signal to a discrete-time signal we replace the time t with nT where n is a sample index. What is T? 

3. In western movies we experience that wagon wheels often look like rolling backward when moving forward. What makes this phenomenon? 

4. Do you agree that the human eye observes moving objects in a complete analog fashion? In other words, our eyes' viewing system is limited to some extent?

5. What is aliasing frequency ? When you sample the frequency of 100 Hz signal with a sampling frequency of 150 Hz, it aliases to what frequency of the signal?