Query Asst 1

course Phy 201

Question: `qExplain in your own words how the standard deviation of a set of numbers is calculated.

First you calculate the mean of the set of numbers. Then you find how much each number deviates from the mean. Next, you square these numbers and find the mean of the squared numbers. Finally, you take the square root of the mean of the squared numbers and that is your standard deviation.

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Self-critique (if necessary): OK

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Question: 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.

When finding the best fist line, you are trying to minimize the differences in intervals between the lines and the points. This means that if you have one point very positive in comparison to the graph you should have another point very negative in comparison to the graph. You can have variation because finding the best fit line is an art. Some people may place the y intercept higher and have a lower slope, while some may place it lower with a greater slope. It varies.

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Self-critique (if necessary):OK

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

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Your solution: Average velocity is the change in distance over the change in time. You can think of this as a rate because it is the change in A over the change in B.

Confidence Assessment: 3

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Given Solution:

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. **

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Self-critique (if necessary): OK

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

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Your solution: Speed= change in distance/ change in time. First you will cross multiply to get Speed(time interval)=change in distance. Then you multiply the two (speed and time interval) and you get the distance moved.

Confidence Assessment: 3

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Given Solution:

** You multiply average speed * time interval to find distance moved.

For example, 50 miles / hour * 3 hours = 150 miles. **

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Self-critique (if necessary): OK

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

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Your solution: Again you set up the formula as being Speed= distance moved/time interval. Then you cross multiply giving speed(time interval)=distance moved. You can then divide distance moved by the given speed which will give you the time interval.

Confidence Assessment: 3

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Given Solution:

** time interval = distance / average speed. For example if we travel 100 miles at 50 mph it takes 2 hours--we divide the distance by the speed.

In symbols, if `ds = vAve * `dt then `dt = `ds/vAve.

Also note that (cm/s ) / s = cm/s^2, not sec, whereas cm / (cm/s) = cm * s / cm = s, as appropriate in a calculation of `dt. **

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Self-critique (if necessary): OK

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

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Your solution: Speed=distance traveled/time interval. Therefore you just divide the distance traveled by the time interval.

Confidence Assessment: 3

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Given Solution:

** 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. **

&#Your work looks very good. Let me know if you have any questions. &#