Can you write a summary for chapter 28?

1. The summary should be 35 lines single space.
2. Use Chapter 8 Summary file to write the summary.
4. No plagiarism.

Textbook:OpenStax College Physics, by P.P. Urone, R. Hinrichs, K. Dirks, and M. Sharma –

Alex Newton Chapter 8 Summary Recitation # 4

Linear Motion is a product of specific systems mass and its velocity. Linear momentum is a vector quantity. Linear motion acts in the same direction as the velocity direction of a body. Several principles have been made to explain the theory behind linear motion. This chapter looks at these set principles which govern bodies in momentum. From Newtons second law of momentum “The net exterior force is the same as the change in momentum of a system allover the time over which it changes”. The relationship between force and momentum exist if and only if mass is a constant. Impulse is an integral of force over an interval of time for which it acts. Since force is a vector quantity, then impulse is a vector quantity acting in the direction of the force. Impulse has a standard unit of measurement usually newton second. Any resultant force causes acceleration resulting to change in the velocity of a body. This depends on the exposure period and the amount of force exerted. A bigger change in linear motion will result from a large force exacted. Momentum can be conserved, revisiting the Newtons law “action and reaction forces are equal and opposite”. This law can be used to prove that in every single interaction there is a pair of contradicting force. For the system of the forces acting against each other to balance, the force should be equivalent. The law of momentum conservation states that for colliding bodies the momentum before and after colliding is equal. This means that the moments lost by the first body should be equivalent to the moments attained by the second body. Elastic impact is an encounter amongst bodies whereby the overall dynamic energy is conserved. Dynamic energy is the work required to speed-up a body whose mass is known from its state of rest to a certain velocity. Energy that a body possess at its state of rest is potential energy. This means that the dynamic energy within the bodies earlier or at the latter of a collision do not change. Net conservation of kinetic energy does not occur because during the collision some energy is transformed to heat or noise. In the energy conversion a state of repulse is reached first (potential energy) before transformation to other forms of energy. An inelastic collision in one-dimension results to a change in the interior dynamic energy which is not preserved. After the impact, the objects may twig together resulting a perfect inelastic collision situation resulting to a reduction in internal kinetic energy. Collision of bodies may occur in two dimensions. This assume a case of a body in motion colliding with a body at rest (velocity=0). After the collision the velocity of the body in motion decrease meaning the collision results to loss in kinetic energy. Lastly, rocket propulsion uses the principle of Newtons third law which conditions action and rejoinder forces to be equivalent and contrary. The acceleration of a skyrocket depends on the drain of blasts velocity which triggers its acceleration. An explanation of skyrocket at the lift-off stage, the motors of the skyrocket force hot air out. Proving the law associated, the burning gases thrust the rocket in the opposite (vertical) direction. This action results to the propulsion of the skyrocket. If the rocket burns its fuel at a faster rate the its acceleration is fast too and finally the slighter the skyrocket mass the higher the rate at which it speeds-up. The thrust increases as the skyrocket reduces its mass meaning that the change in velocity will increase with time. This can also be explained by the reduced pull by the gravitational force.

Requirements for chapter summaries:

1. Each summary must be typed as a SINGLE paragraph with a 12 pt font and single-spaced with 1”

margins on all sides.

2. You must discuss EVERY topic of the chapter for the sections that are listed in the schedule. If you

leave out a topic, then you will get no credit no matter the length of your summary.

3. Each summary must be written entirely in your own words (No equations allowed!). Do not copy the

wording in the textbook or from any other source. Such acts are plagiarism and constitute academic

Academic dishonesty.pdf. Optical character recognition and plagiarism software is ubiquitous and we

use it regularly. You will automatically fail the course if you are guilty of plagiarism to any degree.

4. The very first line will include your name, the chapter number and your recitation section number in the

following format:

Alex Newton Chapter 47 Summary Recitation 03

5. You will skip the second line and start your summary on the third line of the page. Write the entire

summary in a single paragraph. See the example summary at the end of the syllabus.

6. Your summary must contain at least 35 lines of text, covering every section of the entire chapter.

Absolutely no bullets or numbered lists are allowed! If your summary is acceptable, a check-mark will

be place on your quiz or exam. If not acceptable, then no check-mark will be place on the quiz/exam.

7. Only hard copies of each summary are accepted! You cannot submit them via email!

8. Print each summary at least one day before it is due so you don’t miss the deadline because of a printing

problem! You can submit chapter summaries early, if you wish.

9. Each summary must be submitted by 9:25:00 AM (as measured by my timepiece) on the day it is due.

Note that 9:25:01 AM is too late!

10. You must submit your chapter summary either on the table in MH 1005 on Friday morning or give it to

me directly. You are never allowed to submit your chapter summary in any other way.

11. All summaries must be on a SINGLE sheet of paper. If your summary is longer than one page, you can

also use the back of that single sheet of paper.

12. All summaries longer than a single sheet of paper will be thrown away and you will get no credit.

13. Attempting to submit a late chapter summary will result in a penalty (of -2 chapter summaries for each

late chapter summary attempted) to your extra credit score.

14. If you will miss class on a Friday because of an excused absence, you must turn in the summary before

its due date, except in the case of a documented emergency (such as illness).

15. Submitting acceptable summaries for all 16 chapters will result in your final exam score being increased

by 20% of your score. If you submit only some of the summaries, you will receive the appropriate

amount of extra credit (e.g., 9/16 of 20% if you submit 9 acceptable summaries).

16. As an example, if you did all the extra credit and received an 88 on the final, then your extra credit would

be 0.20 × 88 = 17.6, making your final exam score = 88 + 17.6 = 105.6.

17. All summaries must be given directly to me or turned in at the time of the quiz or exam. You can never

give your chapter summary to your TA, put it in my mailbox or slide it under my office door.

18. You can always submit chapter summaries to me early! I encourage you to do that.

On the next page is an example of the correct format for a chapter summary

Alex Newton Chapter 47 Summary Recitation # 3

This chapter discusses the factors which affect the conformation of the doublehelical

deoxyribonucleic acid (DNA) molecule. The conformation of the DNA molecule

is obviously of great importance to its biological function, as described in the

introduction of this chapter. Transcription, the process by which the genetic code is read

from a gene, involves the unwinding of the double helix into a flat structure vaguely

similar to a ladder. The two strands are separated and a single strand of messenger RNA

is created by base-pairing with the template strand. The details of the unwinding of the

double helix will depend on the initial geometry of the double helix. Consequently, it is

important to understand the factors which control the conformation of double-helical

DNA. These factors include the local charges of the DNA molecule, the nature of the

counterion, the Coulombic interaction, the hydrophobicity of the bases, the electrolytic

strength and water content of the environment and bonding with neighboring molecules.

The DNA molecule is composed hydrogen, carbon, nitrogen, oxygen and phosphorous

atoms. Since these atoms have different electronegativities, they do not “share” the

electrons of their covalent bonds equally. This causes atoms with a higher

electronegativity to have a net negative charge while atoms with a lower electronegativity

to have a net positive charge. These locally charged regions interact via the Coulombic

interactions, affecting the conformation of the molecule. Coulombic interactions are also

important since each basepair has a net charge of -2e. All of these Coulombic

interactions are affected by the local water content because of the very high dielectric

constant of water. This makes water a very effective screener of the Coulombic

interaction. Consequently, the water content of the sample can have very significant

affects on the conformation. Similarly, for DNA in solution, the electrolytic strength of

the solution can greatly alter the conformation. The four bases of DNA (adenine,

thymine, guanine and cytosine) are hydrophobic in nature. Consequently they are found

on the inside of the phosphodiester backbones composed of deoxyribose and phosphate

groups. This geometry minimizes interactions between the bases and water. Their base

pairing (A-T and G-C) permits for a smooth double helix since the two basepairs are

almost identical in size. If they were significantly different in size, the phosphodiester

backbone would not be a smooth helix. Van der Waals interactions between stacked

bases affect the temperature stability of the double helix. Hydrogen bonding between the

bases and between the DNA molecule and its local water of hydration also has significant

effects on the conformation of the DNA. Counterions are necessary for DNA to cancel

the -2e charge of each base pair. The various counterions (Na+ or K+, for instance) can

participate in electrostatic bonding between neighboring DNA molecules or molecules

(such as proteins) near the DNA molecules. Such bonding between neighboring DNA

molecules is relevant to our study of chromosomes in which the DNA is packed in a

highly condensed state. Histones (composed of proteins) are incorporated in the

chromosomes by having the DNA wrapped around the histones. These intermolecular

interactions (similar to the intermolecular interactions of solid DNA) are critical for

chromosome’s stability. Exactly how these interactions are modified during the

replication of a chromosome is currently a mystery to science.