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Physics

Demonstration of Mastery Exercises (DOMEs) The activity will involve utilizing a

Demonstration of Mastery Exercises (DOMEs)
The activity will involve utilizing a combination of problem-solving, real-world application, critical thinking, attention to detail, and decision-making.
This exercise involves two parts:
Applying the scientific method to investigate the effects of greenhouse gases and clouds on Earth’s atmospheric temperature using an interactive simulation.
Integrating experiment conclusions and synthesizing related concepts to a) summarize the process of atmospheric heating, and b) evaluate given scenarios where atmospheric warming impacts flight.
The activity will take 2-3 hours to complete and is due at the end of the module.

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Physics

W8: Final Presentation and Course Wrap Up Instructions:  In this discussion, you

W8: Final Presentation and Course Wrap Up
Instructions:  In this discussion, you are asked to share your Presentation with the rest of the class, and to reflect on your progress in accomplishing your educational goals, as you move forward in your academic career. Please upload your presentation (as an “attachment” to your discussion post) and answer the following questions:
What did you like most about this course project? Did it increase your interest in physics?
What was the most interesting thing you observed or researched about the technology topic you chose?
Share any resources you found particularly helpful/useful in the development of your project.
What is your progress in accomplishing your educational goals?
What courses are you starting next month? Why did you choose these courses?
All posts should be readable and use scientific terminology properly.

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Physics

Suppose you could pick any one moon to visit in our solar system. Which one woul

Suppose you could pick any one moon to visit in our solar system. Which one would you pick and why? Describe any unique characteristics of your moon, and include a photo or artist created image (if no photos exist). What dangers would you face on your visit to this moon? What kinds of scientific discoveries or questions would you try to find?

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Physics

There are hundreds of moons in our solar system, and they come in many shapes, s

There are hundreds of moons in our solar system, and they come in many shapes, sizes, and types. Does Kepler’s law of planetary motion apply to moons? Explain.
Why were Kepler’s Laws so important? What paradigm shift took place due to his laws?
If the same force acts on the Moon from the Earth -and- on the Earth from the Moon, why does the Moon orbit the Earth and not vice versa?
How is weight different from mass. If you really just want to weigh less (assuming infinite budget and resources!), what should you do?
Newton’s addition to Kepler’s third law made it possible to know the mass of a star by looking at how planets orbit around it. How would you expect planets move if they orbited a very massive star compared to a very non-massive star (assume the same orbital distance)?

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Physics

What are the major differences and similarities between Aristotle’s view of the

What are the major differences and similarities between Aristotle’s view of the cosmos and Copernicus’s view of the cosmos? Why was Tycho Brahe’s observations and data so important. To what end did they lead? Explain each of Kepler’s three laws as if you were explaining them to elementary aged children. In other words, do not use any mathematical symbols and try to avoid mathematical wording in your explanations of each law. Describe what an observer sees in the sky when a planet undergoes retrograde motion (in terms of direction of motion, time frame, etc.). Then explain the underlying reason is for retrograde motion (in terms of relative planetary orbits). This module largely presented a typical Western European view of the development and history of astronomy. Give at least two examples of non-Western Europeans who contributed to the development of astronomy throughout history. Cite your sources.

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Physics

How could you use the night sky to find north at night? Is this “north” the sam

How could you use the night sky to find north at night? Is this “north” the same as geographic north? Why/why not?
What is the difference between a constellation and an asterism? Give two examples of each
Our modern time-keeping system is based on the Sun. Come up with a way we can keep time using the Moon, instead. How would we determine a “day”? Would how we divide into parts (like hours)? What would a “year” look like?
What is the significance of the ecliptic? Why are the sun, the moon, and the planets only found near the ecliptic?
From which culture(s) did the names of the stars originate? The constellations? There may be more than one answer to each of these questions.

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Physics

THERE ARE 2 QUESTIONS THAT NEED TO BE ANSWERED. ONE PAGE PER QUESTION. THE QUES

THERE ARE 2 QUESTIONS THAT NEED TO BE ANSWERED.
ONE PAGE PER QUESTION.
THE QUESTIONS ARE BASED ON THE ATTACHED IMAGE.
ATTACHED ARE ALSO THE DIRECTIONS FOR THE FORMAT.
1. A friend claims that the “human uses” energy flow in Figure 1.8 is so small compared with natural flows that our energy consumption can’t significantly affect the global environment. How do you reply to this? (1 PAGE)
2. A friend who’s skimmed this chapter thinks it is missing a fundamental energy flow – namely, waterpower. Formulate an argument to counter this claim, and in the process, identity where waterpower fits into the energy flows of Figure 1.8. (1 PAGE)

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Physics

Lab Exercise 1: Electric Fields Refer to the specific outline in your manual for

Lab Exercise 1: Electric Fields
Refer to the specific outline in your manual for the lab Electric Fields.
Follow the instructions and directions below for this lab. Disregard the outline in the manual for your LabPaq Kit. Use the packaging at the tray instead of the petri dish. See Figure 3 below for reference.
Read this document entirely before starting your work.
Do not forget to record your measurements and partial results.
Submit to your instructor the answers to the questions below as well as a Laboratory Report. Remember that the Laboratory Report should include the answers to the questions below.
GOALS
(1) To investigate experimentally the concept of the electric field.
(2) To determine the shape of equal potential lines surrounding charged objects.

INTRODUCTION
An electric field is defined as electric force per unit charge, , with being the electric field vector, being the force vector and q being the charge immersed in the electric field. However, since this lab is focused on studying the relationship between electric field and equipotential lines, we can use the following equation:
We can determine E, the electric field strength at a given point by measuring the potential difference (ΔV) between two points along a line in the direction of the electric field and dividing the potential difference (ΔV) by the distance between these two points (Δx). The units of electric field strength are Newtons/Coulomb or Volts/meter which are their equivalent.
An electric field or force line represents the direction in which a charge would accelerate if moving only under the influence of the electric force. Potential difference denotes the amount of work which would have to be done when a unit charge is moved from one point to another, and equipotential lines are lines of equal electric potential or equal voltage. Electric field lines or electric force lines originate at positive charges and terminate at negative charges; while equipotential energy lines are perpendicular to electric field lines (see figure 1).
Since the direct measurement of electric field lines is quite difficult, and requires specialized equipment, we will use the electric potential energy or the electric potential to map the electric field. We will measure and record the electric potential of numerous points in an electric field using a voltmeter, and then connect points with equal electrical potential thereby producing a “contour plot” of “equipotential” lines. Once such a contour plot of equipotential lines has been produced, the electric field lines can be visualized by superimposing electric field lines so that they intersect the equipotential lines perpendicularly as shown in Figure 2.
Figure 1: (left) Electric fields around positive and negative charges. (right) Equipotential lines (dashed)
IMPORTANT !! Before you start the experimental part of this lab, you MUST read and understand the instructions of the Digital Multimeter (DMM) included in your kit.
PROCEDURE
Place the sheet of graph paper on a table and center the clear tray over the grid. Use the rectangular and not the circular tray for this exercise.

Attach the end of each jumper cable to a metal nut by clamping the free alligator clip onto it as shown in Figure 2.
Figure 2: Probe connection
Place the two metal nut conductors in opposite ends of the clear tray. They should be approximately centered and about 2.5 cm away from the ends of the tray. If needed, you can use a different tray.

Position the battery holder with a 1.5V battery outside of and slightly away from the tray so it cannot get wet. Attach the jumper cables from the two conductors to the battery holder, one to the positive terminal and the other to the negative terminal.

Fill the tray with sufficient water to just barely cover the conductors.
Set your DMM to measure voltage by moving the dial to DCV, and its range to a voltage equal to or higher than that of the 1.5V battery. Again, make sure that you understand how the DMM works.
It is very important that the DMM is set to measure Volts (DCV) rather than current (DCA).
If it is set to measure current, the internal fuse will likely blow.
Attach the negative black lead from the DMM to the negative terminal of the battery holder.

Attach a jumper cable to the positive red lead that comes from the DMM. To the other end of the jumper cable attach the washer.

Figure 3 shows the experimental setup for this lab.
Figure 3: Experimental setup
With the DMM’s positive red lead, touch each of the conductors in the tray and record your findings. When doing this, keep the probes perpendicular to the tray. Keep in mind that:

Touching the negative conductor in the tray should result in a zero volt reading.
Touching the positive conductor should result in a reading that is the same as the battery output.
Touching a distance halfway between the conductors should record a voltage equal to approximately one-half the voltage of the battery. If it does not, stir a few grains of salt into the water in the tray.

QUESTION 1
What is the DMM reading for the voltage of your battery?

You can find grid paper at: http://www.classroomjr.com/printable-graph-paper-and-grid-paper/
Using the second sheet of graph paper, draw the conductors’ locations and label them with the voltage readings of your voltmeter.

Place the positive red lead of the DMM in the water again and note the voltage reading. Move the lead around in such a way that the voltage reading is kept at approximately the same value. How far does this path go?

Sketch this pattern on your graph paper and label the line with the voltage you chose.

Move the positive lead along additional voltage value paths and similarly sketch their patterns on the graph paper until you have well mapped out the area between and around the conductors.

With a color pen or pencil draw a point any place on your map to represent a moveable positive charge. Predict the path it would take by drawing a line with your colored pen or pencil.

Figure 4 below shows an example of the results of a similar experiment. However, in this experiment, the tray was square and the voltage of the probe was 5 V. Your results should be different. We include it here to give you an indication of the type of results you will obtain.

Figure 4: Example of results of a similar experiment
QUESTION 2
What generalizations can you make from this exploration?

QUESTION 3
Imagine that we drop a positive test charge into the tray? Where would it have the least potential energy?

LABORATORY REPORT
Create a laboratory report using Word or another word processing software that contains at least these elements:

Introduction: what is the purpose of this laboratory experiment?
Descriiption of how you performed the different parts of this exercise. At the very least, this part should contain the answers to questions 1-3 above. You should also include procedures, etc. Adding pictures to your lab report showing your work as needed always increases the value of the report.
Conclusion: What area(s) you had difficulties with in the lab; what you learned in this experiment; how it applies to your coursework and any other comments.

Categories
Physics

Does soda really rot tooth enamel?

My three topic choices are:
Does soda really rot tooth enamel?
Can you make flames dance to music?
Does breakfast cereal have real iron in it?

Categories
Physics

What characteristics of fluoroscopic equipment are designed for radiation protection?

Select 8 questions, and answer in paragraph form. Avoid a bullet list but use paragraphs as best as you could.
1. What safety features that reduce patient radiation exposure can be found on state-of-the-art diagnostic radiographic and fluoroscopic equipment?
2. During interventional fluoroscopic procedures, what strategies can be used to manage radiation dose to patients, x-ray equipment operators, and other staff?
3. What are the responsibilities of a radiographer working with a non-radiologist physician, using a C-arm or stationary fluoroscope with HLC mode, while performing an interventional procedure?
4. What results if the x-ray beam and the image receptor are not properly aligned? How can you prevent this error?
5. What characteristics of fluoroscopic equipment are designed for radiation protection?
6. List four factors that are considered when a barrier for a radiographic room is designed.
7. What are the benefits and the consequences of using a radiographic grid when the anatomy to be radiographed is greater than 10 cm?
8. List 3 procedures involving extended fluoroscopic time and why they require longer times
9. Explain how the use of a grid affects radiation dose.
10. Describe scatter radiation