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Unformatted text preview: EGN3353C Fluid Mechanics Spring 2010 ! ! Exam 1 LAST NAME:___________________________ FIRST NAME:________________ SECTION:______
INSTRUCTIONS: Closed book, closed notes, calculator allowed.
1. (5 points) You are given a crown and asked to determine whether it is made of pure gold. You ﬁnd
that the crown weighs 37.91 N in air and 35.96 N in water. First, derive an expression for the
density of the crown. Second, assuming that ρWater=1000 kg/m3 and ρGold=19320 kg/m3, determine
whether the crown is made of pure gold. (Assume purity if the density deviation is less than 1%.) Continue with your answer on the back of this page if necessary EGN3353C Fluid Mechanics Spring 2010 ! ! Exam 1 2. A car has fallen into a river and sunk to the riverbed. The car doors are rectangular with height
a=0.95 m and width b=0.60 m. The water height above the top edge of the door is h=0.050 m. The
pressure inside the car is taken to be atmospheric. Use ρWater=1000 kg/m3 and g=9.81 m/s2.
a. (5 points) Using the direct integration
patm
Air
approach, determine the force required to
open the door, assuming that there is no
Water
h
water in the car, and that the driver
applies the force at a distance of 3b/4
b
Door axis
from the door axis. (Note that the force
due to the pressure will act at a distance
a
of b/2 from the door axis.)
b. (5 points) Now assume that the car is
ﬁlling with water. If the driver can exert a
maximum force of 500 N, up to which
height does the water have to rise relative
to the bottom edge of the door to allow the driver to open the door? Continue with your answer on the back of this page if necessary EGN3353C Fluid Mechanics Spring 2010 ! 3. (5 points) For the multiﬂuid manometer shown on
the right, determine the pressure difference pBpA,
assuming that SG1=1.00, SG2=13.50, SG3=1.26,
SG4=0.88, h1=0.55 m, h2=0.20 m, h3=0.10 m, and
h4=0.12 m. Take ρWater=1000 kg/m3 and g=9.81 m/s2. ! Exam 1 A
Fluid 3
SG 3 Fluid 1
SG1 Fluid 4
SG 4 h1
h3 B
h4
h2
Fluid 2
SG2 Continue with your answer on the back of this page if necessary EGN3353C Fluid Mechanics Spring 2010 ! ! Exam 1 EXTRA SPACE FOR YOUR ANSWERS  INDICATE CLEARLY WHICH PROBLEM YOU ARE WORKING ON Continue with your answer on the back of this page if necessary ...
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This note was uploaded on 09/05/2011 for the course EGN 3353C taught by Professor Lear during the Spring '07 term at University of Florida.
 Spring '07
 Lear
 Fluid Mechanics

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