ENGR 120
Homework 14
NOTE: This is an individual assignment. Use non-engineering format for problem 1, and engineering format for
problems 2 through 4.
1. Consider the data provided below.
(a) Plot this data by hand using linear, semilog and log-log paper. See the graph paper attached at the end of
this assignment. Use proper engineering format.
(b) What mathematical form best fits this data (linear, exponential, power)? Why?
(c) Plot the data using Excel (use the type of plot that results in a straight line from part a) using proper
engineering format. Add a trendline, and find m, b and r2 using the built-in capabilities of Excel.
(d) Use linear regression to find m, b and r2 (by hand).
X
time
(s)
1
10
100
Y
temperature
(K)
10000
170
1
2. Water exits a tube with an inside diameter of 5mm so that 500 grams of water is collected over a 1 minute period.
Determine the velocity of the water at the tube exit. Be sure to carefully include units in your calculations. 0.424 m/s
3. A system pumps water from a valley to an elevation of 5000 m at the top of a mountain where wise engineering
professors meditate. Assuming 50 kg of water is collected every minute at the mountain top and the velocity of the
water is 1 m/s, determine the power (in watts) that would have to be delivered to a pump assuming an overall
pump/piping system efficiency of 25%. Use Mathcad to solve this problem, carefully including units in your solution.
1.63(10)5 W
4. When New Orleans was flooded during Hurricane Katrina, approximately 224 billion gallons of water (a volume of
848 million cubic meters) collected in the city.
(a) If the water had to be pumped an average height of six feet (1.83 m) high to move it to the other side of the
levee system, then determine the potential energy change of the volume of water during pumping (in
Joules). 1.52(10)13J
(b) If electricity costs $0.11 per kilowatt-hour (kwh), how much would it cost to pump the water out of the city?
1000 · 3600
$464,000 Hint: 1
1000
·1
1000 · 1
Cartesian Graph Paper
Semi-Log Graph Paper
Log-Log Graph Paper