Asky diver jumps from a reasonable height above the ground. the air resistance she experiences is proportional to her velocity, and the constant of proportionality is k = 0.19. it can be shown that the downward velocity of the sky diver at time t is given by v(t) = a(1 − e^-kt) where t is measured in seconds and v(t) is measured in feet per second (ft/s). suppose a = 64.
(a) find the initial velocity of the sky diver.
(b) find the velocity after 5 s and after 15 s. (round your answers to one decimal place.)

Asteel tube (k=50 w/mk) of inner and outer diameter di = 20mm and do=26mm, respectively, is used to transfer heat from hot gases flowing over the tube (h-hot = 200w/m2k) to cold water flowing through the tube (h-cold = 8000 w/m2k). what is the cold-side overall heat transfer coefficient uc? to enhance heat transfer 16 straight fins of rectangular profile are installed longitudinally along the outer surface of the tube. the fins are equally spaced around the circumference of the tube, each having a thickness of 2mm and a length of 15mm. what is the corresponding overall heat transfer coefficient uc? *solve for uc in both cases*

How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57×10−21 newtons?

Which if the following types of research is conducted on multiple occasions over time