Consider the following three signals (1) x(t) = sinc(t); (2) y(t) = et sin(f0t)u(t) (3) z(t) = u(t); where the unit step and the sinc functions are de ned as follows: u(t) = ( 1 t > 0 0 else sinc(x) = sin(x) x : (a) Classify them as power or energy signals (b) Compute their energy or power (c) Compute the autocorrelation function of x(t)

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.