ENGR 160 Exam 1
Spring 2014
Name
Page 1 of 7
Engineering Problems: _____ /50
Programming:
_____ /50
TOTAL:
_____ /100
DIRECTIONS: This exam is CLOSED BOOK. The reference sheet plus one extra page of notes may be consulted during the
exam. Print your name on all pages. Only specified types of calculators are permitted. Express all answers in the proper number of
significant digits unless directed otherwise.
Engineering Problems
1.
(10%) For full credit you must show all your work clearly.
a.
Determine the hydrostatic pressure in a lake at a depth of 20.0 feet in units of pascals, Pa.
The equation for hydrostatic pressure, PHydro, is given below:
PHydro = ρ g H, where ρ = density of fluid
g = gravitational acceleration
H = height of fluid
Use the standard density of water for the density of the fluid in the lake (1000.0 kg/m3).
b.
A basketball has a diameter of approximately 27 centimeters. Find the volume of the basketball in units of gallons.
ENGR 160 Exam 1
Spring 2014
Name
Page 2 of 7
2.
(15%) For the problems below you must SHOW ALL YOUR WORK clearly.
a.
Pure methyl alcohol is being pumped at the rate of 3.76 x 103 gallons per 12.0 hour period. Given the density of methyl alcohol
is 51.2 pounds-mass per cubic foot, find the equivalent mass flow rate of the methyl alcohol in base S.I. units (mass/time).
b.
Convert 55 million gal/day to m3/s
c.
Convert 3.17 ft3/min to L/hr
ENGR 160 Exam 1
Spring 2014
Page 3 of 7
(15%) In an experiment, the numbers of failures were recorded as a function of time in hours. Using the method of selected points
the following points were selected off the best fit straight line: A(1.0, 4.0) and B(5.4, 630.0).
You are to finish the methods of selected points procedure by calculating the parameters m and b of the best fit line.
State the equation in general form, using appropriate variables and significant digits.
Failures vs Time
M Selby, 9/19/11
1000
Failures, F, # of
3.
Name
100
10
1
0.1
1
Time, t, hours
10
ENGR 160 Exam 1
Spring 2014
4.
Name
Page 4 of 7
(10%) The volume of water in a reservoir is often expressed using the unit of acre-foot. A volume of 1.0 acre-foot is the
amount of water covering an area of 1.0 acre to a depth of 1.0 foot.
Lake Mead 1 is the largest man-made lake in the United States. It holds approximately 28.5 million acre-feet of water behind the
Hoover Dam.
Convert this volume to units of gallons. Show all your work clearly.
1
By the way, Lake Mead was named after Elwood Mead, head of the US Bureau of Reclamation under Calvin Coolidge. Mead got
his PhD in civil engineering (studying water resources) from Iowa State in 1883.
ENGR 160 Exam 1
Spring 2014
Name
Page 5 of 7
Programming
5.
(20%) Write a complete program which takes values for a hollow metal sphere and calculates the volume of the metal material
and the mass of the metal. The program will:
• Prompt the user to enter outside radius in meters, density of metal in kilograms per cubic meters and the wall
thickness in meters
• Calculate the volume of metal in the hollow sphere in cubic meters
• Calculate the mass of the metal in the hollow sphere in kilograms
• Output to the screen the volume and mass with units labeled
• Allow the user to indicate whether they want to enter another wall thickness and redo the calculations for volume and
mass
• Stop when the user indicates they don’t have any other wall thickness values to enter
ENGR 160 Exam 1
Spring 2014
6.
Name
Page 6 of 7
(18%) Write a program that will ask the user to input an angle in degrees, x and then calculates a value, y according to the table
below. The program should output both x and y, with labels to identify the values.
For
For
For
x ≤ -180˚
-180˚ < x ≤ 180˚
180˚ < x
→
→
→
y = -x – 180˚
y = sin(x)
y = -x + 180˚
ENGR 160 Exam 1
Spring 2014
Name
Page 7 of 7
7. (12%) The velocity a rocket travels upward as a function of time (in seconds) is given by v = 1.3t − 0.00152t (where
velocity is in m/s). Write a complete VBA program to calculate and output the time and velocity of the rocket from 30 to 0
seconds (counting down) in increments to be input by the program user. So if the user input an increment of 3 the time would
begin like this: 30, then 27, then 24, then 21, . . . Your output must include time and velocity, both well labeled including units.
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