course Phy121

Sir, I have fallen behind due to my teaching school responsibilities. I will try to get all assignments done. They might not be on time but I will try. If you could indulge me and let me finish them for at least a C grade,I will give you my best learning effort. I did not realize the extensive assignments of the course and got my book 2 weeks late.

assignment #001001.

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

Physics I

02-18-2007

......!!!!!!!!...................................

21:40:55

Explain in your own words how the standard deviation of a set of numbers is calculuated.

......!!!!!!!!...................................

RESPONSE -->

First, find the mean of the data and find the regular deviation by subtracting from the data in the set.

Square the deviation.

Add the products of deviation then divide by n-1 to get the product, take the square of the product of deviation.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:44:08

Explain in your own words the process of fitting a straight line to a graph of y vs. x data, and briefly discuss the nature of the uncertainties encountered in the process. For example, you might address the question of how two different people, given the same graph, might obtain different results for the slope and the vertical intercept.

......!!!!!!!!...................................

RESPONSE -->

The fitting of a line to data graph can be interpreted differently by the origin of the slope-intercept point. Thus people could view the same graph differently by using different m-values in y=mx+b.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:45:18

Briefly state what you think velocity is and how you think it is an example of a rate.

......!!!!!!!!...................................

RESPONSE -->

Rate can be defined by change in something divided by another value that shows change.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:45:56

** A rate is a change in something divided by a change in something else.

This question concerns velocity, which is the rate of change of position: change in position divided by change in clock time. **

......!!!!!!!!...................................

RESPONSE -->

exactly

self critique assessment: 3

.................................................

......!!!!!!!!...................................

21:46:45

Given average speed and time interval how do you find distance moved?

......!!!!!!!!...................................

RESPONSE -->

Multiply average speed by the interval in time to find distance.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:48:00

Given average speed and distance moved how do you find the corresponding time interval?

......!!!!!!!!...................................

RESPONSE -->

the time interval is equal to the distance divided by average speed.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:50:44

Given time interval and distance moved how do you get average speed?

......!!!!!!!!...................................

RESPONSE -->

Divide the distance moved by the total time traveled.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

21:51:02

** Average speed = distance / change in clock time. This is the definition of average speed.

For example if we travel 300 miles in 5 hours we have been traveling at an average speed of 300 miles / 5 hours = 60 miles / hour. **

......!!!!!!!!...................................

RESPONSE -->

yep

self critique assessment: 3

.................................................

Good. Let me know if you have questions.

Continue to remind me on a weekly basis that your bottom-line goal is to make a C. You're obviously capable of doing much better, but this is a time-consuming course and I fully understand and support your goals. Keep reminding me and whenever possible I'll advise you accordingly.

course Phy121

1. If the velocity of the object changes from 3 cm / sec to 11 cm / sec in 9 seconds, then at what average rate is the velocity changing?11 cm/s – 3 cm/s / 9sec = 8cm/9sec = .88 cm/s per sec

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

2. A ball rolling from rest down a constant incline requires 8.6 seconds to roll the 68 centimeter length of the incline.

• What is its average velocity? 68cm / 8.6s = 7.91 cm/s

3. An object which accelerates uniformly from rest will attain a final velocity which is double its average velocity.

• What therefore is the final velocity of this ball?

• What average rate is the velocity of the ball therefore changing? ? 68cm / 8.6s = 7.91 cm/s

4. An automobile accelerates uniformly down a constant incline, starting from rest. It requires 15 seconds to cover a distance of 172 meters. At what average rate is the velocity of the automobile therefore changing?

172m / 15s = 11.46cm/s

Godo work. Let me know if you have questions.

course Phy121

assignment #002002. `Query 2

Your work has been received. Please scroll through the document to see any inserted notes (inserted at the appropriate place in the document, in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.

Physics I

02-18-2007

......!!!!!!!!...................................

22:16:04

How is acceleration an example of a rate of change?

......!!!!!!!!...................................

RESPONSE -->

Velocity is the rate of change of postion, acceleration is rate of change of velocity, change in velocity divided by time.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

22:18:17

If you know average acceleration and time interval what can you find?

......!!!!!!!!...................................

RESPONSE -->

You have to know how fast the object is moving or the only thing you can find is the change in velocity.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

22:20:17

Can you find velocity from average acceleration and time interval?

......!!!!!!!!...................................

RESPONSE -->

No, you can only find change in velocity not velocity itself. More information is needed.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

22:32:28

Can you find change in velocity from average acceleration and time interval?

......!!!!!!!!...................................

RESPONSE -->

Change in velocity is average acceleration multiplied by the change in time. The average acceleration could be multiplied by the time interval to find the change in the velocity.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

22:35:24

Can you find average velocity from average acceleration and time interval?

......!!!!!!!!...................................

RESPONSE -->

average velocity is change in positoin divided by the change in time.

Acceleration and velocity are indirectly related.

confidence assessment: 3

.................................................

......!!!!!!!!...................................

22:38:42

You can find only change in velocity from average acceleration and time interval. To find actual velocity you have to know at what velocity you started. Why can't you find average velocity from acceleration and time interval?

......!!!!!!!!...................................

RESPONSE -->

Average velocity is change in position/change in time.

confidence assessment: 2

.................................................

......!!!!!!!!...................................

22:50:49

Principles of Physics Students and General College Physics Students: Problem 14. What is your own height in meters and what is your own mass in kg, and how did you determine these?

......!!!!!!!!...................................

RESPONSE -->

73in. * 2.54cm = 185.42cm height

315 lbs * 1kg/2.20 lbs = 143.18 kgs

confidence assessment: 3

.................................................