1. (10 pts) At an average rate of 100 per second, what fraction of the intervals between randomly occurring events are shorter than 10 ms?

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1. (10 pts) At an average rate of 100 per second, what fraction of the intervals between randomly occurring events are shorter than 10 ms?
2. (10 pts) A measurement of possible Cs-137 contamination on an air filter is made on a daily basis. The measurement consists of placing the filter on a counting system with an absolute counting efficiency of 15% at 662 keV for a period of 30 min. A new uncontaminated filter is then substituted in the counting system and another 30 min background count recorded. The background count averages 100 counts per minute.
a. Where should the critical level LC be set (in units of counts per 30 min measurement) to declare the positive presence of contamination following the criteria outlined in the MDA discussion?
b. Under these conditions, find the minimum detectable amount (MDA) of Cs-137 on the filter as defined in the same discussion.
3. (10 pts) Counters A and B are nonparalyzable with dead time of 30 and 100 us, respectively. At what true event rate will dead time losses in counter B be twice as great as those from counter A?
4. (10 pts) A paralyzable detector system has a dead time of 1.5 us. If a counting rate of 105 per second is recorded, find the two possible values for the true interaction rate.
5. (10 pts) Sketch both the differential and integral pulse height spectra (using the same horizontal scale) for the following cases:
a. Pulses with single amplitude of 1 V
b. Pulses uniformly distributed in amplitude between 0 and 1 V
c. Pulses distributed around an average amplitude of 1.5 V with a pulse height resolution of 8%

1. An amateur astronomer has a telescope to examine distant stars and nebulae. The focal length of the main objective lens of the telescope is f= 710 mm. At what distance from the lens will a distant star be imaged using this objective lens?

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1. An amateur astronomer has a telescope to examine distant stars and nebulae. The focal length of the main objective lens of the telescope is f= 710 mm. At what distance from the lens will a distant star be imaged using this objective lens? Give your answer in units of metres.
2. The human eye has a nominal lens to retina distance of Si= 1.7 cm = 0.017 m . What does the focal length of the lens in the eye need to have if the Object to lens distance (So) is:
a) So = 15 cm= 0.15 m
b) So = 1m
c) So = 15 m
d) So = 100000 km = 108 m
The human eye has an internal lens component that it can flex to change the effective cornea/ lens focal length. Using the results from parts a) through h) what is the percent change in focal length over the wide distances seen by the eye from very close to very far? Explain.
3. A cell phone has a fixed focal length lens of f = 3.85 mm = 0.00385 m and can take pictures over a range of distances from So = 0.5 m to So = infinity. Over what range of distances (Si) does the lens in the cellphone have to move to focus an image at these two extremes in object distance?
4. A microscope is being used to study cells on a slide. The lens to image distance is Si in the microscope is Si = 160 mm = 0.16 m. If a microscope objective of focal length f= 12.5 mm = 0.0125m is used, how far is the object to lens distance (So).

1. Why do electrons (blue dots) move? Draw a diagram of the battery, label the flow of electrons. The flow of current (+) is opposite; draw this and note if toward or away from + terminal of the battery.

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1. Why do electrons (blue dots) move? Draw a diagram of the battery, label the flow of electrons. The flow of current (+) is opposite; draw this and note if toward or away from + terminal of the battery.
2. What does the Ammeter (on the left) measure? How is this shown in the sim?
3. What role do the “green dots” in the resistor play in the sim? What do you think they represent? What does this tell you about the effect of resistors in a circuit?
4. Increase the resistance (# green dots). What affect does this have on temperature? WHY?
5. When the circuit gets hotter, what affect does this have on current? Explain using kinetic-molecular theory.
6. To make the circuit “cold”, what do you need to do? WHY?
7. Describe the relationship between voltage and temperature.
“Resistance in a Wire”:
1. In this sim, what variables are you seeing the relationship of. Write the formula below, and indicate the units used to measure each one.
2. Try increasing the resistivity of the resistor, r. How does this change the “look” of the resistor? Describe how that relates to the formula you just wrote (direct, indirect relationships, etc.). What happens to the value of “R” (Resistance)? Is this something that can be changed in a resistor that you would buy in a store to use in a circuit?
3. Now increase the length (L) (you would essentially be designing a different resistor, since you can’t do this to one you will be using in a circuit).What happens to “R”? WHY?
4. Now increase the area (A) of the resistor. What changes? WHY?
5. Write a summary about the different relationships you looked at in the properties and measurements of a resistor.
“Ohm’s Law”:
In this sim, vary the values of Resistance (R), Current (I) and Voltage (V).
1. What are three different combinations of I and R which get a voltage of 6.0 Volts?
2. Describe the relationship between I and R. Why is this?
3. What would happen if you could decrease the resistance to 0? Explain.
Go to http://phet.colorado.edu/en/simulation/battery-resistor-circuit
and click on Run Now.
Batteries, Resistance and Current
“Battery-Resistor”:
Check “show battery” and “show cores”, watch what happens, adjust some variables

. State both the primitive and the modern definitions of time. Which do you find the more reasonable?

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1. State both the primitive and the modern definitions of time. Which do you find the more reasonable?
2. The viscosity is measured as follows. Write each in acceptable form using base units only: a} 17/9800 Pa · s b) 32/8741 N · s/m2 c) 61 /34 982 kN · h/mm2
3. Round off 6743.865 to:
a) Six significant digits
b) Five significant digits
c) Four significant digits
d) Three significant digits
e) two significant digits
4. Write the viscosity p = 0.001 Pa · s using newtons and not pascals. Also write the viscosity without using either newtons on pascals.
5. Write the heat flux density 300 W/m2 with the units in the following forms: a) one that includes joules b) one that includes newtons c) one that includes kilograms
6. Write each of the following in a correct form without using any exponents: a} 12300 Nmkg-1 K-1 b) 109.433 Cs m-1 K-1 c) 0.000433 W s m-3 K-1

1. Two hundred cubic feet of air at 14.7 psia is compressed to 90 psig. What volume of receiver is required?

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1. Two hundred cubic feet of air at 14.7 psia is compressed to 90
psig. What volume of receiver is required?
A.28.1 ft
B.32.7 ft
C. 39.0 ft
D. 41.3 ft
2. A pressure of 87 psig is measured on the inlet side of a pneumatic line filter, and a pressure of 83 psig is measured on the outlet side of the filter.
Which of the following is correct?
A.This is an example of static pressure, and no gas is flowing.
B.This is an example of a pressure drop, and gas is flowing through the filter.
C.The pressure should increase across the filter which therefore must need to be cleaned or replaced.
D. The filter isn’t working correctly; no pressure drop should be present at any time.
5. Which of the following statements is true?
A.Atmospheric pressure is about 29.4 psig.
B.101 kPa is about 10.1 psi.
C.30 psia is the same as 15.3 psig.
D. 2.1 MPa is the same pressure as 21 kPa.
6. A closed receiver of compressed air has a volume of 10 cubic feet and a pressure of 90
psig. A valve is open that then connects an additional 5 cubic feet of volume due to the
piping and tubing from the system. What will the new gauge pressure be?
A.45 psig C. 69 psig
B.55 psig D. 180 psig
11. Two thousand cubic feet of gas that’s compressed from a free pressure of 14.7 psia to a
working pressure of 90 psig
A.will have a much greater volume.
B.won’t have much energy stored in its volume.
C.requires special compressors to reach the desired pressure.
D. will likely have its temperature raised significantly as it’s compressed.
12. In a closed pneumatic system (maintaining a constant volume), you know from the general
gas law that if you decrease the
A.volume, the temperature will remain the same.
B.temperature of the gas, the pressure will increase.
C.pressure, the temperature will increase.
D. pressure, the temperature will decrease.
15. A cylinder has a 3.0-inch bore and a 0.75-inch diameter rod extending from both sides of
the piston. If the cylinder is pressurized by 100 psig air so that the rod is extended, what
force is developed by the cylinder?
A.100 lbs.C. 663 lbs.
B.300 lbs.D. 707 lbs.
16. Air is flowing through an intake line to a compressor. If the inside diameter of the line is
2.5 inches and the air is moving at a velocity of 40 feet per second, what is the volumetric
flow in cubic feet per minute (CFM)?
A.0.114 CFM C. 40 CFM
B.196.3 CFM D. 81.8 CFM
17. A pipe must carry about 10 CFM of air at a maximum velocity of 25 feet per second. What
should the minimum pipe inside diameter be?
A. inches C. 1.1 inches
B.1.0 inches D. 1 Inches
18. Gas is put into a receiver at a temperature of 150°F and a pressure of 120 psia. After
being cooled to 60°F, what is the pressure of the gas in the receiver?
A.48 psia C. 140.8 psia
B.102.3 psiaD. 300 psia
19. An air cylinder has a 4.0-inch bore and a 1.25-inch rod diameter. How much must the
pressurization on the retraction stroke be increased to maintain the same force for both
extending and retracting?
A.10.8% C. 22.4%
B.12.5% D. 68.8%

A double-acting cylinder with a 3.0-inch bore operates at 75 psig. It has a stroke of 12 inches and completes 10 complete extend-and-retract strokes per minute. What is the required airflow to this cylinder?

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A double-acting cylinder with a 3.0-inch bore operates at 75 psig. It has a stroke of 12
inches and completes 10 complete extend-and-retract strokes per minute. What is the
required airflow to this cylinder? You can ignore the rod diameter for the retract stroke.
9. A volume of 7.5 ft of air is compressed to 2.2 ft. The compression ratio is
A. 4.1. C. 3.4.
B. 2.2. D. 0.29.
11. A pneumatic pipe that’s 60 feet long should have a slope with a drop of about _______
inches from one end to the other.
A. 1.2 C. 7.5
B. 6.0D. 18.0
12. If allowable motor duty cycle is 80%, what size compressor in SCFM is required to supply
a pneumatic system that consumes 60 CFM at 75 psig?
A. 516C. 814
B. 542D. 458
13. Approximately what motor Hp will be required for a two-stage compressor for a 250 SCFM
pneumatic system that operates at 100 psig?
A. 44.75 C. 25.0
B. 41.0 D. 100
16. What is the force required from an actuator to move a 28-pound bracket across a metal
table if the coefficient of sliding friction is 0.28?
A. 5.6 lbC. 28 lb
B. 7.8 lbD. 100 lb
B. 7.8 lbD. 100 lb
17. A pneumatic cylinder must lift a 14-pound weight a distance of 6 inches. The inertial load
is calculated to be 10.5 pounds. What approximate minimum force should be specified for
the cylinder in this application?
A. 11 lb C. 25 lb
B. 15 lb D. 50 lb
18. What would be the minimum bore size for a cylinder if it needed to develop 550 pounds of
force and operate from a pressure of 110 psig?
A. 2.52 in C. 2.98 in
B. 2.75 in D. 3.15 in
19. What torque is produced by a 2.5 Hp air motor that operates at 1800 rpm with 80 psig air
pressure?
A. 9.0 lb-inC. 87.5 lb-in
B. 32 .0 lb-in D. 720 lb-in