Lecture Notes

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- 1-54 (2nd: 57): What mass (lbm) would generate 85,000 lbf of weight due to gravity?
- 2-25: In transporting liquids, pressures can drop. What happens to a liquid when its pressure drops? Cavitation is a major safety concern!
- 2-80 (2nd: 76): Please take the time to relate the drag force to the velocity profile. WHERE do we evaluate the drag? If two velocity profiles have the same slope at the wall, but different velocity profiles in the middle, will the drag be the same or different?
- 3-24 (2nd: 20): What would happen if the piston where free to move further than 3 m? That is, what if it just kept on going?
- 3-86 (2nd: 3-80): Part b: you will need to equate moments and use the center of pressure (see pg 89). The force on a surface can be evaluated using the pressure at the CENTROID. That force then acts AT the CENTER OF PRESSURE. Use Fig. 3-31 (2nd: 3-30), Eq. 3-22b.
- (2nd: 3-98) Note: the book's answer of 1.05 m is wrong (if that's the number in your printing).
- 5-W1: The axial velocity profile for laminar flow in a pipe is given by u(r) = Umax * (1-r*r/(R*R)) where r is radial position, R is the pipe radius, and Umax is the maximum velocity. For R=1 m, and Umax=1 m/s, compute the volumetric flow rate. What value do you get if you assume the velocity is uniform at the average velocity?
- 5-51 (2nd: 49): See table A-11.
- 5-W2: Please read and comprehend Book examples 5-5 through 5-9 in your text. Just write "did it" for your homework.
- HW 12: Click Here
- HW 17: Click Here
- HW 19: Click Here
- 6.28 (2nd: 26): Make sure you can do problem 6-25. You need a relative velocity since the cart is moving.
But don't neglect the proper treatment of mdot.

- Hint: Problems 9-30, 31, 34, and 38 are in the "Continuity Equation" section of the homework.

- 9-36 (2nd: 31): When you integrate dy/dx = x^2 you get y=x^3/3 + c. If instead we have y=y(x,z) and the derivative is a partial derivate, the integration gives c=c(z). That is, instead of a constant of integration, we get a function of integration that is a constant with respect to the integration variable, in this case c(z).
- 9-89 (2nd: 91): Read and understand Example 9-14, which is very similar to this problem.
(Of course, you knew that, because you did your reading :-)

- HW 26 problem: Click Here
- HW 28