Category: Physics

What is the velocity (magnitude and direction) of the two children after they collide? Your answer should be significant to two digits.

Watch Segment D (Vectors and Scalars), Segment E (Graphical Resolution of Vectors) and Segment F (Mathematic Resolution of Vectors) at https://www.gpb.org/physics-in-motion (The GPB Physics In Motion video series). Then write answers to the following questions, showing all your calculations.

[a] A child with mass Y kilograms (kg) who is skating eastward in a hockey rink at Y centimeters per second (cm/s) runs into another child, also with mass Y kg, who is skating northward at Z cm/s. The children grab onto each other and keep moving across the ice. Draw a diagram of this interaction, labeling all the relevant objects, quantities, and velocity vectors before and after the collision.

[b] What is the velocity (magnitude and direction) of the two children after they collide? Your answer should be significant to two digits.

[c] Do you think these two children are likely to have been injured in the collision? In a paragraph of at most 50 words, explain using scientific and mathematical reasoning why you think so or not.

List any reference sources, such as books or websites, if you used them to help you come to your conclusion.

If a hockey puck of mass Y grams (g) is moving at Z centimeters per second (cm/s), what is the momentum of this puck in units of kilogram meters per second (kg m/s)?

Watch Segment B (Scientific Notation and Unit Conversions) and Segment C (Significant Figures) of the Physics in Motion series https://www.gpb.org/physics-in-motion and compute and write answers to the following questions.

If a hockey puck of mass Y grams (g) is moving at Z centimeters per second (cm/s), what is the momentum of this puck in units of kilogram meters per second (kg m/s)?

If a child with mass Y kilograms (kg) is being accelerated in a car at 0.89 meters per second squared (m/s2), then how much force is being exerted on that child? You may choose what units to use to express that force; in this instance, your answer is significant to only two digits.

In 20-40 words, explain why you think scientists make such a big deal about significant digits. Why should we not, for example, just write down all the digits on your calculator screen as an answer to a math-based science problem?

Create a question about a person experiencing X newtons of force that uses Newton’s Third Law of Motion to answer it. Then answer it. You will be evaluated on both the appropriateness of the question and the correctness of the answer.

What do you think is the longest half-life of a radioactive isotope that could be used for medical imaging? Explain your answer, and write down one or two other interesting things you learned in Section 32.1 of the text.

In the OpenStax College Physics textbook, read the first part of Chapter 32 (Medical Applications of Nuclear Physics) up through and including Section 32.4 (Food Irradiation). Based on that reading, answer each of the questions below, in about 30-50 words each.

[a] What do you think is the longest half-life of a radioactive isotope that could be used for medical imaging? Explain your answer, and write down one or two other interesting things you learned in Section 32.1 of the text.

[b] How do the units rem, rad, and Ci (curie) mathematically convert to the units Sv (Sievert), gray (Gy), and Bq (bequerel) respectively? Also, write down one or two other interesting things you learned in Section 32.2 of the text.

c] Do you know or have you read about anyone who has had radiation treatments for cancer? If not, fmd such a story on the intemet about such a person. Briefly, what course of treatment did they experience? How does that information relate to what you read in Section 32.3 of the text?

[d] If you eat food from supermarkets or restaurants, then you have almost certainly eaten irradiated food throughout your life. What one or two interesting things did you read about in Section 32.4 might affect how you feel about eating irradiated food in the future?

How does this video’s presentation of Karl Popper’s idea of science as falsifiability connect with the concepts expressed in Lecture 02 about what science is? If it doesn’t, explain why not.

For the following questions, handwrite all your answers on a separate sheet of paper. You must write your solutions by hand, cite all your references, and show all your calculations.

[a] Read the essay “Science as Falsification” by Karl Popper. Then write a 30-50 word summary of what you feel are the main ideas of this essay. Based on your reading, do you agree with Karl Popper’s definition of science? (The essay is at staff.washington.edu/lynnhank/Popper-l.pdf or eportfolios.macaulay.cuny.edu/liu10/files/2010/08/Kpopper_Falsification.pdf) Why or why not?

[b] Watch the Crash Course Philosophy video #8 at youtube.com/watch?v=-X8Xfl0RITQ (Karl Popper, Science, and Pseudoscience). Answer in roughly 50 words this question: How does this video’s presentation of Karl Popper’s idea of science as falsifiability connect with the concepts expressed in Lecture 02 about what science is? If it doesn’t, explain why not.

[c] Referring to the video in Part [b] above, what are one or two big ideas expressed between 6:00 and 8:00 of Crash Course Philosophy #8 that have made an impression on you? Explain why they made an impression on you personally.

[d] Go to youtube.com/playlist?list=PLIjnepQR5pV-3iTxs34-GIZsSRwHQso5r [Science Forward Class Videos]. Look through it; choose two videos in the playlist to watch except for the first one. Watch those videos; write down their title, why you chose the video, one person that spoke about their scientific work on the video, and one idea that is particularly interesting to you. Your answer for each video should be roughly 50 words in length.

This is a mathematical exercise. Using the relationship “force equals mass times acceleration,” write an answer to the following question: if an object with mass X grams is being accelerated at Z centimeters per second squared, then how much force is being exerted on the object? Show your calculations on the page.

 What do you think is the longest half-life of a radioactive isotope that could be used for medical imaging? Explain your answer, and write down one or two other interesting things you learned in Section 32.1 of the text.

What do you think is the longest half-life of a radioactive isotope that could be used for medical imaging? Explain your answer, and write down one or two other interesting things you learned in Section 32.1 of the text.

How do the units rem, rad, and Ci (curie) mathematically convert to the units Sv (Sievert), gray (Gy), and Bq (bequerel) respectively? Also, write down one or two other interesting things you learned in Section 32.2 of the text.

Do you know or have you read about anyone who has had radiation treatments for cancer? If not, fmd such a story on the intemet about such a person. Briefly, what course of treatment did they experience? How does that information relate to what you read in Section 32.3 of the text?

If you eat food from supermarkets or restaurants, then you have almost certainly eaten irradiated food throughout your life. What one or two interesting things did you read about in Section 32.4 might affect how you feel about eating irradiated food in the future?

What is Physics? Physics In Motion). How does the defmition of physics presented in this video compare to that from the video in Question 4 above?

[a] Watch the video https://youtube.com/watch?v=GOuZkYDQjpc (Dianna’s Intro Physics Class: Trailer). As presented in this video, what is physics? Is it consistent with your experiences with physics to date, and why? (Your answers should total 30-50 words.)

Watch the video https://www.youtube.com/watch?v=G2vpZR_q-CI

(What is Physics? Physics In Motion). How does the defmition of physics presented in this video compare to that from the video in Question 4 above? Based on this definition, give an example of physics in your own life. (Your answers should again total 30-50 words.)

Discuss one or more ways that the article is directly tied to the topics covered in this module regarding the science of flight planning.

Module 6 Discussion
• Paragraph 1:

Briefly summarize, in your own words, the aircraft accident based on your research. In your summary, highlight the causes of the accident based on the results of the accident investigation.

• Paragraph 2:

Discuss one or more ways that the article is directly tied to the topics covered in this module regarding the science of flight planning.

• Paragraph 3:

Give us “your take” on the relevance and importance of the summarized accident or incident, and the importance of flight planning in general, by providing personal points of view or related experiences.

Identify the total mechanical energy conservation.In an isolated system, a 2kg ball with an initial velocity of 3 m/s hits a 5 kg ball that is initially at rest. What is the total kinetic energy before the collision? If the total kinetic energy after the collision is the same as that before the collision, is this an elastic collision or inelastic collision?

Unit IV problem solving worksheet
This assignment will allow you to demonstrate the following objectives:

4. Apply the concept of momentum conservations to daily life.
4.1 Relate impulse-momentum theorem to Newton’s second law.
4.2 Show the relationship between linear momentum conservation and Newton’s third law.
4.3 Apply momentum conservation to rotational kinematics.

5.Identify the total mechanical energy conservation.
5.1 Interpret total kinetic energy conservation in elastic collision.

A boy exerts an average force of 100 N on a shopping cart for 0.5 seconds. What is the impulse? Hint: See Sample Question 1 in the Unit IV Lesson.

In an effort to participate in a science fair, Alice designed a toy car engine that can generate a total impulse of 100 Ns. The mass of the toy car is 2 kg. What is the final speed that her toy car attains when moved from rest? Ignore frictional forces. Hint: See Sample Question 2 in the Unit IV Lesson.

Curious George observed an interesting event in an international toy exhibition. Two toy cars were moving forward in a monorail. Toy car #1, weighing 10 kg, was ahead of toy car #2, weighing 20 kg, in the beginning, but they collided and joined together. The initial velocity of toy car #1 is 10 m/s and that of toy car #2 is 20 m/s. What is the final velocity of both of these cars after they are connected? Assume that there is no friction in this system. Hint: See Sample Question 3 in the Unit IV Lesson and Example 5 on page 181 to 182 in the textbook.

In an isolated system, a 2kg ball with an initial velocity of 3 m/s hits a 5 kg ball that is initially at rest. What is the total kinetic energy before the collision? If the total kinetic energy after the collision is the same as that before the collision, is this an elastic collision or inelastic collision? Hint: See Sample Question 4 in the Unit IV Lesson and Example 7 on page 185 in the textbook.

Consider an inelastic collision between a green ball and an orange ball. The mass m of the green ball is 1 kg and the mass M of the orange ball is 3 kg. Before the collision, the orange ball was at rest and the initial velocity of the green ball was 5 m/s. After the collision, they were combined as one object as shown in the following. What is the final velocity V? Hint: Use the momentum conservation law.

A wheel spins counterclockwise through three revolutions for 2 seconds. What is the average angular velocity of the wheel? Hint: See Example 3 on page 204 in the textbook.

The fan blades of a jet engine in an airplane rotate counterclockwise with an initial angular velocity of 100 rad/s. As the airplane takes off, the angular velocity of the blades reaches 400 rad/s in 10 seconds. Calculate the average angular acceleration. Hint: See Example 4 on page 205 in the textbook.

A new car takes 10 seconds to accelerate from rest to 30 m/s. Its mass is 1500 kg. What is the net average force that acts on the car? Hint: Use the equation (7.3) on page 176 in the textbook.

A 2 kg ball, moving to the right at a velocity of 2 m/s on a frictionless table, has an elastic head-on collision with a stationary 5 kg ball. What is the total kinetic energy before the collision? What is the total kinetic energy after the collision?

Starting from rest, Amy and Jane push off against each other on the smooth frictionless ice rink. The mass of Amy is 50 kg and that of Jane is 60 kg. Amy moves to the right (positive direction) with a velocity of 3 m/s. What is the recoil velocity of Jane? Hint: See Example 6 on page 182 in the textbook.

Explain numerous phenomena using fluid mechanics laws.A 10-kg piece of metal displaces 0.002 m3 of water when submerged. What is the density of the metal? Hint: Use the formula mass = density x volume.

Unit VI Problem solving worksheet
This assignment will allow you to demonstrate the following objectives:

6.Explain numerous phenomena using fluid mechanics laws.
6.1 Utilize the relationship between mass, density, and volume.
6.2 Apply the concept of Pascal’s principle and Archimedes’ principle.
6.3 Recognize heat and energy with phase changes of matter.

If the mass of air inside a room is 1 kg, what is the volume of the air? Use Table 11.1 on page 290 in the textbook. Hint: Review Sample Question 1 in the Unit VI Lesson.

A massless cube container holds water whose density is 1000 kg/m3. The length of the side of the cube is 7 meters. What is the mass of the water? Hint: The volume of a cube is obtained by R x R x R, where R is the length of the side of the cube. Use the formula mass = density x volume.

A 10-kg piece of metal displaces 0.002 m3 of water when submerged. What is the density of the metal? Hint: Use the formula mass = density x volume.

The pressure acting on a floating piece of wood is measured by 12345 Pascal, and its surface area is 0.6789 m2. What is the magnitude of the force in Newtons? Hint: Review Example 2 on page 292 in the textbook.

A boy’s height is 1.76 meters. The vertical distance from his head to his heart is measured as 0.39 m. Find the blood pressure difference between the blood pressure in the anterior tibial artery at the foot and the blood pressure in the aorta at the heart. What is the blood pressure difference between them? The density of blood is 1060 kg/m3, and the blood is assumed as being a static fluid. Hint: Review Sample Question 2 in the Unit VI Lesson.

You bought a 1 kg solid gold statue from a merchant in Italy while you are on vacation. When you get home, you decided to test if this statue is real gold or not. After submerging the gold statue in a large water container, you will measure the volume of displaced water. What is the expected volume if the statue is made of pure gold? For the density of gold, use Table 11.1 on page 290 in the textbook.

A traveler at the North Pole measured the temperature as -40oC. Can you convert this temperature to the Fahrenheit scale? What is the temperature on the Kelvin scale? Hint: Use the converting formula: oF = 1.8oC + 32. The relation between the Celsius scale and the Kelvin scale is K = oC + 273.15.

A runner who weighs 50 kg produces 500,000 J of heat for a half hour, but this heat is removed by various mechanisms inside of her body to adjust to the conditions. However, if the heat was not removed, what is the increment of temperature? The specific heat capacity of the human body is 3500 J / kg oC from Table 12.2 on page 340 in the textbook. Hint: Review Sample Question 4 in the Unit VI Lesson and Example 9 on page 340 to 341 in the textbook.

In order to freeze 2 kg of water at 0oC into ice at 0oC, how much heat is required? The latent heat of fusion for water L = 335,000 J / kg. Hint: Review Sample Question 5 in the Unit VI Lesson.

In 1965, Penzias and Wilson discovered the isotropic cosmic background radiation of the microwave and earned the Nobel Prize in 1978. The cosmic microwave background radiation is measured by 2.725 Kelvin through the entire sky. Convert this temperature into the Celsius scale as well as the Fahrenheit scale. Hint: Use the converting formula: oF = 1.8oC + 32. The relation between the Celsius scale and the Kelvin scale is K = oC + 273.15.

Review the following resources on density altitude and its effects on flying

Density Altitude

Review the following resources on density altitude and its effects on flying:
Hot, High, and Heavy-The Deadly Cocktail of Density Altitude (PDF)
Don’t Be Dense About Density Altitude (Plane and Pilot)
Density Altitude (Mountain Flying)

Density Altitude (PDF) (Federal Aviation Administration)
The following video is a historic mid-century FAA film discussing the important aspects of density altitude:

Density Altitude with Harry Bliss (YouTube – 29:00)
This video, from the view of the cockpit, captures the density altitude-related crash of a general aviation aircraft:
Airplane Crash In-Cockpit Footage: Stinson 108-3 (YouTube – 3:50)