course Phy 121 õ™“÷œkŽÏ’ǘŒ†ûNvØáËl ¸i§öN°ÞñÈŸàassignment #001
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00:25:10 Explain in your own words how the standard deviation of a set of numbers is calculuated.
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RESPONSE --> Standard Deviation is calculated by first finding a mean by finding the summation of the numbers in a set and dividing it by the total of numbers in the set. Each individual number is then subtracted from the mean and then squared and summed. The square root is then taken and you have the standard deviation. confidence assessment: 2
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00:27:36 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.
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RESPONSE --> To fit a straight line, you look at the set of points and insert a line that best fits the data and does not connect the points dot to dot. It is a personal judgement and observation and different people can come up with different slopes and different intercepts based on how they as individuals perceive the graph. confidence assessment: 2
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00:30:25 Briefly state what you think velocity is and how you think it is an example of a rate.
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RESPONSE --> Velocity is distance over time. It can be the number of meters traveled per seconds used to get that far. Velocity is an example of a rate because in order to go a certain distance it is dependent on a certain amount of time. The two measurements rely on each other to obtain data. Rate is also how often something changes. confidence assessment: 2
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00:30:41 ** 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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RESPONSE --> okay self critique assessment: 2
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00:31:32 Given average speed and time interval how do you find distance moved?
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RESPONSE --> Average speed is a distance/time. Given a time interval you just multiply the time interval by the average speed in order to obtain the distance moved. confidence assessment: 3
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00:31:40 ** You multiply average speed * time interval to find distance moved. For example, 50 miles / hour * 3 hours = 150 miles. **
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RESPONSE --> right self critique assessment: 2
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00:32:31 Given average speed and distance moved how do you find the corresponding time interval?
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RESPONSE --> Average speed is distance/time. Given distance moved you divide average speed by the distance in order to obtain the time interval. confidence assessment: 2
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00:33:11 ** 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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RESPONSE --> I believe I divided backwards, not sure about my wording. self critique assessment: 2
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00:33:33 Given time interval and distance moved how do you get average speed?
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RESPONSE --> Average speed is calculated by distance divided by time interval. confidence assessment: 2
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00:33:40 ** 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. **
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RESPONSE --> right self critique assessment: 2
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