This preview shows pages 1–6. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: ME 370 Practice Exam 3 Fall 2010 ME 370: Engineering Measurements and Instrumentation
Fall 2010
Practice Exam 3 Name: 5.0511,,” Section: NOTE: This is a practice exam, it, by no means, should be identical to the real exam. It is solely used for
practice purpose, provides some general idea on the real exam. PLEASE READ THE FOLLOWING INSTRUCTIONS .. ,. For the multiple choice and true/falseproblems, please‘WRlTE IN your answer clearly andlegib‘ly in the
indicated space for each problem. . _ ' ' " Please write down justiﬁcation or calculations to support your~ answers. For problems involving
calculations, you may not be awarded points if you do not show your work.  This is a closebook, close note exam  you areNOT allowed to use the assigned course textbook. You are allowed a single 8.5 ” x 11"‘shee‘t (bothisides) of notes. The note sheet has to be handwritten and
to be made by yourself. Photocopies or printed version is not allowed. You'must attach your note sheet
with your exam and turn it in. {I , v '
By writing your name on this sheet, you agree to abide by the honor system and uphold academic
integrity. WARNING: Cheating on the exam constitutes academic fraud and will result in an automatic
failing grade for the course. ' ' ' ' ME 370 Practice Exam 3 Fall 2010 Problem 1 (35 points): A second order transducer can be modeled as 0.0137 + 1.457 + 1003/ = F (t). For
such as system I (A) Determine the natural frequency of the system (5 points)
(B) Determine the damping ratio of the system (5 points)
(C) Determine the static sensitivity of the system (5 points)
(D) Assume the damping ratio of the system is 0.7, and the natural frequency is 100 Hz, the system
static sensitivity is 5 V/N, and the input signal is F(t) = 5 + 5 sin(50t) + 10ccs(20t), what is the
steady output signal (15 points), and the frequency spectrum of the signal (5 points) goiw’ﬁon: ?.blb‘+l.\\—§g.+lbug. o‘ol M ~
I»? q .—
\°.;’ 3 [email protected] W)
,L“ 7'5 ‘ ~ I (:9)
mfg] +151.” +3 “k1: (C) \A 3 7‘; '1 ~99 (9) ‘F‘C‘Ujf ‘FLLU :YSTn for T3: {0 0,; 20+
ALT'5‘ (PVT—3" A5310 (P539) Wu 72,741" 3, psi £3,052
PW We? 97 91m .2 pink) :15
Tats?) 7? f) ,L (f) ; 3L. N1LW1JALQU; Pig 4; ti L)
M5092.) '5 “L/ lb. ‘93,): 2r4u2(§°t#o.nn) ME 370 Practice Exam 3 Fall 2010 Problem 2 (20 points): The following plot depicts an experimental magnitude response of the a 2'1d order
system with different frequency sinusoidal input. We know that the natural frequency of the 2nd order system is 100 Hz, A) What is the range of damping ratio of the second order system? (5 points)
B) If a dynamic error of i5% is desired, what the input frequency range you can use? (5 points)
C) If this system is used to measure vibration, what range of Vibration frequency you can measure (10 points) I
I

_



L.



L. ME 370 Practice Exam 3 Fall 2010 Problem 3 (45 points): An aerospace engineering student performs an experiment in a wind tunnel to
determine the lift coefﬁcient of an airfoil. The student takes 61 measurements of the vertical force using a
force balance, yielding a sample mean value of 44.20 N and a sample variance of 4.00 N2. Determine (a)
the probability that an additional measurement will be between 45.56 N and 48.20 N (20 points), (b) the
range (in N) over which the true mean value will be, assuming 90% conﬁdence (10 points), and (c) the
range (in N2) over which the true variance will be assuming 90% conﬁdence (15 points). Hwﬂg ME 370 Practice Exam 3 Fall 2010 Bonus problem (10 points): The second order force measurement system damping ratio and natural
frequency can be determined experimentally by supplying a step input and measure the response, as shown in Figure below. (A) Derive the equations for the damping ratio (5 points)
(B) Derive the equations for the natural frequency (5 points) Displacement ...
View
Full
Document
This note was uploaded on 09/20/2011 for the course ME 370 taught by Professor Chung during the Spring '09 term at Iowa State.
 Spring '09
 CHUNG

Click to edit the document details