Category: Science Homework Help

I need help in making a chemistry project on the composition of stars and comets. It has to be a power point presentation where you can orally explain it in a minimum of 5 minutes and maximum of 7 minutes. Facts has to be from a total of 3 sources cited. Chemical Structures and formulas have to be included. As relevant as possible to chemistry and also a personal point of view. Help as soon as possible would be greatly appreciated. Thank you.

The Joint Commission reported that [poor] communication was the root cause of 66% of Sentinel Events between 1995-2005. Examine the communication and collaboration in your workplace. Include these aspects:

• The components necessary for effective interpersonal communication.
• Discuss the importance of interprofessional collaboration.
• Apply components of interpersonal communication to interprofessional collaboration.
• Discuss strategies to promote interprofessional collaboration.
• Describe effective strategies to build interprofessional teams.
• Cultural competence

I’m working on a anatomy writing question and need support to help me study.

Now that you have learned about the eleven body systems in the human body, as well as the organs and functions that each contain, I would like you to pick your favorite body systems and begin to think about this body system in more detail.  In your response, include the following details.  

Please number your response from 1 to 4. 

1. Include all the organs that make up this body system.
2. Explain how each of the organ’s function help achieve the overall function of the organ system you chose.
3. Explain why this is your favorite body system.
4. Give one disease that afflicts this body system and explains what specific organ or organ is affected by this disease.

Background:

The social construct of race is often use as an example of how culture shapes our perceptions of others based on outward biological variation. Here, I would like to explore two recent anthropological studies that challenge other common assumptions in many societies.

Instructions:

These two studies use biological anthropology (combined with archaeological evidence in the case of the big game hunter) to challenge popular notions of societal norms and biological variation in humans. Read each article and answer the questions below.

Upload your final answers as a PDF or Word file or enter into the text box.

1) First, this publication by Holly Dunsworth Download this publication by Holly Dunsworthlooks at alternative explanations for biological sex differences in humans.

• What is sexual dimorphism?
• What popular concepts are being challenged?
• What evidence does Dr. Dunsworth use to back up her ideas? (i.e. What may be the underlying cause for these differences?)

2) Second, this publication indicates that women likely participated in big game hunting around 9000 years ago (Links to an external site.).

• What popular notions of gender roles are challenged by this research?
• Why do these researchers think past big game hunting by women was more common than previously thought?

3) What is the relevance of these two studies to one another? (Hint: Be sure to read the end of Dunsworth’s paper.)

my favorite animal is penguin

Annotated bibliography: first You will identify and briefly describe five information
resources for your “favorite animal” presentation

second: You will give a PowerPoint presentation on the natural
history, evolution, and taxonomy of your favorite animal or taxon

I’ve been struggling with this one for a while. I have a few equations I’ve tried but I really want to see a good solution, neatly written so I can understand.

Video of freezing point depression lab

The video below presents the major steps for determining the freezing point depression of a pure substance. At the end of the video, a sample calculation is presented for determining the molar mass of the unknown. There are some differences between this lab and our lab, however. They are listed next:

• The video examines the freezing point depression for cyclohexane. In our lab, we will consider freezing point depression of lauric acid.
• Cyclohexane is a liquid at room temperature, whereas lauric acid is a solid at room temperature. In our lab, the amount of lauric acid is measured by taking its mass on an analytical balance.
• Since cyclohexane is a liquid at room temperature, its freezing point is determined by placing cyclohexane in an ice-water bath. For lauric acid, it must be heated first, then the substance freezes as it returns to room temperature.
• Our lab manual contains a section called Part II, which is optional. This video does not cover the optional procedure. Likewise, we will not consider Part II in this lab. We will only focus on Parts I and III.

As you are watching the video, record your qualitative observations in your lab notebook.

For your lab, you will be given data that you will analyze. The video given above is only example of what a similar lab experiment is like. For your data, you will need to assume that the lab was conducted as described in the lab manual.

Lab

Objective

• Using complete sentences, write the main objective(s) for this lab.

Part I

• The purpose of part I is to determine the normal freezing point of the pure solvent, lauric acid.
• The cooling curve for a pure substance should look like the graph below. We will only be looking at the boxed portion of the full cooling curve.

Edit

• The freezing point of the pure substance should be the flat region of the curve that occurs following any observed supercooling. Sometimes supercooling is not observed.
• Diagram below shows example experimental data. There is a small amount of supercooling, followed by a somewhat flat region. This flat region represents the freezing temperature. The sloped region at the end represents the stage where the frozen substance cools after completely freezing.

Part III

• The purpose of part III is to determine the new freezing point when there is solute in dissolved in the solvent. The change in the freezing point of the pure solvent vs. the solution can be used to determine the molal concentration of solute particles that make up the solution.
• Adding the unknown causes the freezing point to be not as sharp. That is, freezing will occur over a wider range.
• The freezing point of the solution will be lower than the freezing point of the pure substance. This is the colligative property known as freezing point depression.
• A comparison of the cooling curves for the pure and impure substance is given in the diagram below.

• The diagram above exaggerates the differences for the segments of a typical cooling curve. For experimental data, the boundaries between the different sections is often more subtle. For example the section where the impure substance freezes and where the solid is cooling can be difficult to distinguish.
• Below is an example of experimental data for the freezing of a solution. Notice it is difficult to determine where freezing occurs and where freezing is complete (and the solid is cooling). However if you look closely, there is a section where the cooling curves levels off before temperature begins falling at a faster rate.

Cooling Curve of a Solution

• To estimate the freezing point for the solution, extrapolate a line of best fit for the liquid cooling section and the freezing section. The temperature where the lines intersect is the estimated freezing point for the solution (shown in the image below)

EditEditEditEditEditEditEdit

Tasks:

This exercise asks you to complete the following

• • .
• Title Page
• Results and Calculations
  • Organize and present your data using the results that were provided to you.
    • Part 1:
      • the freezing points from each trial
      • the average freezing point for pure lauric acid
      • percent error from actual freezing point of lauric acid
    • Part III:
      • the mass of unknown and lauric acid used for each run
      • the molal concentration of unknown for each run
      • the individual freezing points from each trial
        • report the ΔT for each trial, but do not average them. It is inappropriate to average the ΔT for part III since they should be different depending on how much unknown was added.
      • the individual molar mass for the unknown, calculated from each run
      • the average molar mass for the unknown
      • the percent error for your molar mass, assuming your unknown is benzoic acid.
    • Show sample calculations for
      • molal concentration of unknown
      • moles of unknown
      • percent error
    • Create tables summarizing the major experimental data.
• Conclusion
  • Evaluate the objective(s) of the experiment and restate the freezing point and percent error of lauric acid, and the molar mass of the known and percent error.
• Post Lab Questions
• Spreadsheet download
• Provided Data

I’m working on a physics multi-part question and need an explanation to help me learn.

1) A 1m vertical pendulum has an angle of 20 degrees and a bob of mass 0.8kg.

a) Find the driving force experienced by the bob half angle way down the swing. b) Is the pendulum bob moving in URM? c) Can you find the formula for centripetal force experienced by the pendulum bob half angle way down? If yes write it down. Hint: Find the tangential speed at that point (half angle way down). d) What is angular frequency of this pendulum for small angles?

2) A leaver of length 20m weighs 5kg, it has a mass m1 at the left end and a mass m2 at the right end m1=12kg and m2=9kg at what length from the left end should the fulcrum be placed such that this system will be in equilibrium? Show your work.

3) What is the time of impact of a ball with mass 0.5kg that strikes a wall with a force of 12N and has a change in momentum of 6kgm/s. Also what is the change in speed of the ball?

4) A mass of 10kg travels to the right at a rate of 12m/s and strikes another mass having 4 times the mass at rest. By what percent will the final speed of these two masses change if the collision is completely inelastic?

5) Derive the equation of period for a simple pendulum swinging with a small angle. Show all work. 

I’m working on a physics spreadsheet and need an explanation and answer to help me learn.

each group has an assigned set of 3 forces and you will apply the force method to find a 4th force to make the whole system in equilibrium. enter work here with answers for 4th force clearly marked.