{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Midterm Exam, Spring 2009

Midterm Exam, Spring 2009 - Midterm Exam AEP 2640 Spring...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Midterm Exam, AEP 2640, Spring 2009 Open book and notes; internet access is forbidden Time limit: papers will be collected at 4:00 1. Fluid Mechanics (36 pts) (A) ( 12 pts ) Calculate the horsepower needed to overcome drag on a sports car moving at a speed of 85 mph if the projected frontal area is 20 ft 2 and the drag coefficient at that speed is C D =0.38. Assume that the air density and kinematic viscosity are 0.074 lb/ft 3 and 1.56x10 -5 m 2 /s, respectively. [1 horsepower = 746 watts; 1 lb = 0.454 kg; 1 mile = 5280 ft; 1 inch = 2.54 cm] (B) ( 12 pts ) If we take a characteristic dimension “d” for the car to be given by the expression: πd 2 /4 = 16.5 ft 2 , calculate Re d . (C) ( 12 pts ) Would you expect the boundary layer over the car’s top surface to be laminar or turbulent? Why? 2. Error Analysis (36 pts) Ten independent measurements of the length and diameter of a circular cylinder of gold are given below: length (mm) diameter (mm) 20.025 4.875 19.975 4.900 19.975 4.850 20.000 4.875 19.950 4.850 19.950 4.900 19.925 4.925 19.950 4.950 20.000 4.950 20.050 4.975 (A) ( 12 pts ) What is your estimate of the standard deviation for each separate
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern