Suppose u(x, t) measures the concentration of a substance in a moving stream (moving with velocity v). suppose the concentration u(x, t) changes both by diffusion and convection; derive the equatiorn from the fact that at any instant of time, the total mass of the material is not created or destroyed in the region [x, x + ax] hint write the conservation equation change of mass inside [x, x + ax] = change due to diffusion across the boundaries + change due to the material being carried across the boundaries

In 1980, alfa romeo introduced the first system to smooth a rough idle caused by ignition and camshaft timing changes.

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

Asilver dollar is dropped from the top of a building that is 1324 feet tall. use the position function below for free-falling objects. s(t) = −16t2 + v0t + s0 (a) determine the position and velocity functions for the coin. s(t) = v(t) = (b) determine the average velocity on the interval [1, 2]. ft/s (c) find the instantaneous velocities when t = 1 second and t = 2 seconds. v(1) = ft/s v(2) = ft/s (d) find the time required for the coin to reach the ground level. (round your answer to three decimal places.) t = s (e) find the velocity of the coin at impact. (round your answer to three decimal places.) ft/s