1. A signal given by x(t)=2cos(3pi t) is sampled at a frequency of 20 Hz, starting at time t=0. i. Is the signal sampled frequently enough? Why.
ii. Find the first six samples of the sequence.
111. Add delay to the sampled signal given in (b) by four samples. Draw the new one.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.

The characteristic roots of a dynamic system are: 1.7920 1.8160 i, -1.7920 1.8160 i, -0.4160 what is the order of this system? what are the settling time and damping ratio of the system?