What Do Unit Step and Unit Impulse Mean in Systems Control?

[socrates_1]

Homework Statement

Hi,can someone explain to me through real world examples what the unit step and unit impulse means in systems control?How are they related to the system's input? Thank you.

Homework Equations

δ(t) = unit umpulse
u(t) = unit step

The Attempt at a Solution

 

[rude man]

Well, for one thing they ARE system inputs.

If you have a network with a battery as input, and you throw a switch which changes the input to your network from 0 volts to E volts, then your system input is E*u(t).

δ(t) is more complex. Picture a voltage E again, but this time throw the switch on and off for a very short time T. By 'very short' I mean much shorter than the shortest time constant in your network. Then the input to your network is E*T*δ(t) volts.