Where: V = Cross Sectional Average Velocity (M/S)

Leader: Shannon Title Course: ENGR 160 Supplemental Instruction Instructor: Iowa State University Date: 12/7/17

1. The Manning formula is the most commonly used equation to analyze open channel flows (i.e. water flowing in a channel or culvert where the water is open to the atmosphere and not flowing under pressure).

Where: V = cross sectional average velocity (m/s) k = constant (the units on the are what you are to find) n = Manning coefficient (dimensionless) A = cross sectional area of flow (m2) P = wetted perimeter (m) s = slope of channel (m/m)

In the Manning equation the constant k has ‘hidden’ units in it to make the equation consistent. Solve for the units of k.

1060 Hixson-Lied Student Success Center v 515-294-6624 v [email protected] v http://www.si.iastate.edu 2. The angle bracket is loaded as shown in the diagram below. It is connected with a hinge/pin type connector at point A and a roller/ simple support at point B. The mass of the bracket is negligible. Assume all numbers are given to at least three significant digits.

b) Write the three equilibrium equations.

c) Determine the unknown forces at connectors at points A and B (give magnitude and direction of the forces). 3. A college student borrows $5,000 on Jan. 1st, 2014, then borrows $4,500 on Jan. 1st, 2015 and then borrows $5,500 on Jan. 1st, 2016. The payment on the loans is deferred while the student is still in school and the student does not have to start making payments on the loans until 6 months after they graduate. In this case, the student will make her first monthly payment on Dec. 1st, 2016. The loans will be repaid by making monthly payments for 10 years, starting with Dec. 1st, 2016 payment (The last payment will be due on Nov. 1st, 2026). The annual interest rate on all of the loans is 6.5%, compounded monthly.

a. Draw one complete timeline starting with Jan. 1st, 2014 and continuing until Nov. 1st, 2026. Be sure to clearly label the time periods and the cash flows.

b. Determine the total amount owed by the student on June 1, 2016.

c. Determine the amount of the monthly payments, which start on Dec. 1st, 2016. The student will make one payment each month to pay off the three loans. 4. Write a VBA Function subprogram (only, no main program) which will be sent a two- dimensional array which contains real numbers and an integer number, N which represents the number of rows and columns in the array (it’s a square array with the same number of rows and columns). The Function will calculate the sum of the elements above the diagonal of the array. The sum will be returned to the main program. The diagonal is a line of elements starting in the upper left hand corner and ending in the lower right hand corner. There should not be any input or output statements in the Function.

An example of the array is shown below, the 1.0’s are on the diagonal. In this example the sum = 14.0.

1.0 6.3 4.2 2.1 1.0 3.5 0.5 5.3 1.0 5. Write a main program that will prompt the user to enter the daily high temperatures (in Fahrenheit) for the month of December into a one-dimensional array. The program will calculate the average daily temperature for the month, and the range (the difference between the highest value and the lowest value). The program will output these two values to the screen. 6. Write a one Subroutine subprogram (only, not the main program) which will receive average exam scores from the different sections of Engr 160 in a one-dimensional array, X and a count of the number of sections, N. The Subroutine will calculate the mean and the standard deviation of the class averages. The Subroutines will also determine the z-score* of each class and assign those to a one-dimensional array. The overall mean, standard deviation, and an array of z-scores will be returned to the main program.

*The z-score is a measure of how far an individual observation is from the mean, expressed as a fraction of the standard deviation. We calculate the z-score for an observation, by this expression:

Where is the individual class average, is the mean of the averages and s is the standard deviation of the averages.

Recall also that where is the individual value, and n is a count

of the number of values.