Sample HW08 - PHYS 21800

Transcription

Sample HW08 - PHYS 21800
Sample HW08 - PHYS 21800
1
This print-out should have 9 questions.
Multiple-choice questions may continue on
the next column or page – find all choices
before answering.
What mass can it support in water before
sinking?
Holt SF 09Rev 18
001 10.0 points
A piston A has a diameter of 0.63 cm, as
shown. A second piston B has a diameter of
2.2 cm.
Serway CP 09 33
005 10.0 points
An empty rubber balloon has a mass of
0.0127 kg . The balloon is filled with helium
at a density of 0.184 kg/m3 . At this density
the balloon has a radius of 0.54 m .
If the filled balloon is fastened to a vertical
line, what is the tension in the line? The
acceleration of gravity is 9.8 m/s2 .
561.2 N
F
B
A
In the absence of friction, determine the
! necessary to support
magnitude of the force F
the 561.2 N weight.
Correct answer: 46.0207 N.
Deep in the Ocean
002 (part 1 of 2) 10.0 points
Engineers have developed a bathyscaph that
can reach ocean depths of 10.9 mi.
If the density of seawater is about
1030 kg/m3 , what is the absolute pressure
at that depth? The acceleration of gravity is
9.8 m/s2 .
1 mile = 1609.0 meters
003 (part 2 of 2) 10.0 points
If the inside of the vessel is maintained at
atmospheric pressure 1.013 × 105 Pa, what
is the net force on a porthole of diameter
18.9 cm?
Holt SF 09A 02
004 10.0 points
A 3.4 kg rectangular air mattress is 2.66 m
long, 0.868 m wide, and 0.178 m thick.
Correct answer: 407.581 kg.
Correct answer: 7.02464 N.
Density of air
is 1.29 kg/m^3
Holt SF 09Rev 62
006 10.0 points
A cowboy at a ranch fills a water trough that
is 1.4 m long, 70 cm wide, and 47 cm deep. He
uses a hose having a diameter of 2.3 cm, and
the water emerges from the hose at 1.2 m/s.
How long does it take the cowboy to fill the
trough?
Serway CP 09 45
007 10.0 points
A jet of water squirts out horizontally from a
hole on the side of the tank as shown below.
Sample HW08 - PHYS 21800
2
Correct answer: 14.3312 m/s.
Take the speed of
the water level here
to be zero.
h
009 (part 2 of 2) 10.0 points
Applying Bernoulli’s principle, what is the
pressure P1 at the entrance end of the pipe?
Correct answer: 1.57433 × 105 Pa.
1.54 m
0.538 m
If the hole has a diameter of 3.81 mm , what
is the height of the water above the hole in
the tank?
Correct answer: 4.69877 cm.
Constricted Pipe 03
008 (part 1 of 2) 10.0 points
A liquid of density 1265 kg/m3 flows with
speed 2.12 m/s into a pipe of diameter 0.13 m .
The diameter of the pipe decreases to 0.05 m
at its exit end. The exit end of the pipe is
8.99 m lower than the entrance of the pipe,
and the pressure at the exit of the pipe is
1.4 atm .
P1
2.12 m/s
0.13 m
P2 1.4 atm
8.99 m
v2
0.05 m
What is the velocity v2 of the liquid flowing
out of the exit end of the pipe? Assume the
viscosity of the fluid is negligible and the fluid
is incompressible. The acceleration of gravity
is 9.8 m/s2 and Patm = 1.013 × 105 Pa.