Air enters an elbow with a uniform speed of 10 m/s as shown in Fig. P4.67. At the exit of the elbow, the velocity profile is not uniform. In fact, there is a region of separation or reverse flow. The fixed control volume ABCD coincides with the system at time t 0. Make a sketch to indicate (a) the system at time t 0.01 s and (b) the fluid that has entered and exited the control volume in that time period.

Chemical Tools: Experimentation and Measurement • Recognize the seven basic SI units of measure. • Give the numerical equivalent of the common metric prefixes used with these units. • Express numbers in scientific notation. • Determine the number of significant digits in a measured quantity. • State the result of a calculation involving measured quantities to the correct number of significant digits. • Convert temperatures between the Celsius and Kelvin scales. • Relate density to mass and volume. • Set up and solve problems using dimensional analysis. CHAPTER 1 – The Structure and Stability of Atoms • Give the symbol and name of the first 36 elements of the periodic table. • Identify the group and period to which an element belongs. • Identify the regions of the periodic ta