Time and Date Stamps (logged): 12:49:22 05-21-2012 °±Ÿ³¸Ÿ±±¯´Ÿ±°Ÿ±¯°± Physics II

Principles of Physics (Phy 122) Test_Set_5

Completely document your work and your reasoning.

You will be graded on your documentation, your reasoning, and the correctness of your conclusions.

** Write clearly in dark pencil or ink, on one side of the paper only. **

Date and Time are 02-15-2001 19:24:47

Signed by Learning Lab Attendant: ______________________

Date and Time: ______________________

Attendant:

Test is to be taken without reference to text or outside notes.

Calculator is allowed.

No time limit but test is to be taken in one sitting.

Please place test in Dave Smith's folder when completed.

Student:

Completely document your work.

Undocumented and unjustified answers may be counted wrong.

Besides undocument and unjustified answers, if wrong, never get partial credit.

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Problem Number 1

Water is confined to flow through a tube whose cross-sectional radius decreases from .16 m to radius .032 m.  If the flow speed at the .16 m cross-section is 3 m/s, what is the flow speed at the .032 m cross-section?

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Problem Number 2

Find the average force on a wall exerted by the particles in a cylindrical container contains 660 * 10^6 particles, each of mass 4.389881E-07 Kg.  The particles collide elastically with a wall at a velocity of 102.7 m/s, and particle directions are randomly distributed in 3 dimensions.   The wall is one of the parallel walls of a cylinder, separated by 95 meters from its counterpart.

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Problem Number 3

A thermal engine takes in 800 Joules of thermal energy, and 736 Joules of thermal energy are removed or dissipated during a cycle.    What is the efficiency of the engine?

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Problem Number 4

A calorimetry experiment indicates that 213.18 Joules of energy are required to increase the temperature of a 17 kg sample of the substance by 19 degrees Celsius.  What is the specific heat of the substance?

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Problem Number 5

At a depth of 6 meters beneath the surface of a body of water, how much force is exerted by pressure against a rectangle whose dimensions are 8 m by 8.1 m?

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Problem Number 6

A uniform cylinder of cross-sectional area 58 square meters is filled with water to a depth of 85 meters above its outflow valve.

By how much does the potential energy of the system, as measured with respect to the outflow valve,  increase if water is pumped in from the level of the outflow valve until the depth increases to 85.49 meters?

If water is then allowed to flow from the cylinder through the small outflow valve until the water returns to its original level, what will be the total kinetic energy of the outflowing water and what will be its average speed, assuming no dissipative losses?

Solve this problem by energy considerations only.   Then solve using Bernoulli's Equation. 

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Problem Number 7

The system is observed to have a pressure of 92.1 kN/m^2 when its volume is 1.1 m^3.  What is the pressure when the volume is increased to 4.4 m^3, assuming that the system is closed and that it is maintained at a constant temperature?

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Problem Number 8

A wall conducts thermal energy at the rate of 162.8 watts.  The wall has cross-sectional area 13 m^2, thickness .15 m and inside and outside temperatures 155 and 10 Celsius.  What is the thermal conductivity of the material of which the wall is composed?

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Problem Number 9

If in a fluid of density 1000 kg/m^3, confined to run in a series of full pipes, the velocity of the fluid changes from 8 m/s to 7.1 m/s with no change in altitude, what will be the change in pressure?  Assume that no dissipative forces act on the fluid.