E2.4 A laser printer uses a laser beam to print copy rapidly for a computer. The laser is positioned by a control input r(t), so that we have Y(s) = 4(s + 50) R(s) s 2 + 40s + 300 The input r(t) represents the desired position of the laser beam. (a) If r(t) is a unit step input, find the output y(t). (b) What is the final value of y(t)?

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

Lymphocytes known as blastocysts make antibodies that fight infection. select the best answer from the choices provided t f

What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?