course Phy 201 浦I鲸s獅利忇簷瘭锪吐晒餺馻ssignment #001
......!!!!!!!!...................................
20:00:26 Explain in your own words how the standard deviation of a set of numbers is calculuated.
......!!!!!!!!...................................
RESPONSE --> Steps: 1. Find intervals and mean of intervals 2. Determine how far each interval is from the mean. 3. Square the differences between the mean and the intervals. 4. Take the average of these numbers by adding them all together and dividing them by one less than the number of numbers that were initially added together. 5. Take the square root of the average for the final answer to the standard deviation. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:13:33 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 --> 1. Find the most extreme points in the data. 2. Find the slope between these points. 3. Choose a point and use the coordinates from the point and the derived slope from above to complete the formula y=mx+b to find b (the y intercept) of the graph. 4. Fill back in the slope (m) and the y intercept (b) to have the equation of the best fit line. Uncertainties include having to estimate the slope using only two points. One person might choose two different sets of points than someone else, yielding slightly different slopes. Of course, any differences in rounding could yield different results too. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:15:22 Briefly state what you think velocity is and how you think it is an example of a rate.
......!!!!!!!!...................................
RESPONSE --> Velocity is basically the same as speed except that it has emphasis on direction. from the equation d=rt, rate = distance/time This is basically the same equation as velocity, which is V=(change in distance)/(change in time) So, the equations are basically the same--velocity is a test of rate that is merely a bit more specific confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:15:35 ** 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 --> I understand. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:16:25 Given average speed and time interval how do you find distance moved?
......!!!!!!!!...................................
RESPONSE --> Average Speed=change in distance/change in time If given average speed and the time, one can solve backwards by multiplying the time by the average speed, yielding the distance moved. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:16:37 ** You multiply average speed * time interval to find distance moved. For example, 50 miles / hour * 3 hours = 150 miles. **
......!!!!!!!!...................................
RESPONSE --> I understand. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:17:47 Given average speed and distance moved how do you find the corresponding time interval?
......!!!!!!!!...................................
RESPONSE --> Avg speed=distance/time To find the time interval, one would multiply the distance by the average speed. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:18:56 ** 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. **
......!!!!!!!!...................................
RESPONSE --> Darn... I swear I meant that. Obviously, if one has the equation avg speed=distance/time, the progression would be as follows: average speed x time=distance time=distance/average speed I understood this before, but was silly and typed the wrong thing! I am fairly confident in this. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:19:19 Given time interval and distance moved how do you get average speed?
......!!!!!!!!...................................
RESPONSE --> One can divide the distance by the time interval. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:19:25 ** 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 --> self critique assessment: 3
.................................................
"
course Phy 201 浦I鲸s獅利忇簷瘭锪吐晒餺馻ssignment #001
......!!!!!!!!...................................
20:00:26 Explain in your own words how the standard deviation of a set of numbers is calculuated.
......!!!!!!!!...................................
RESPONSE --> Steps: 1. Find intervals and mean of intervals 2. Determine how far each interval is from the mean. 3. Square the differences between the mean and the intervals. 4. Take the average of these numbers by adding them all together and dividing them by one less than the number of numbers that were initially added together. 5. Take the square root of the average for the final answer to the standard deviation. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:13:33 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 --> 1. Find the most extreme points in the data. 2. Find the slope between these points. 3. Choose a point and use the coordinates from the point and the derived slope from above to complete the formula y=mx+b to find b (the y intercept) of the graph. 4. Fill back in the slope (m) and the y intercept (b) to have the equation of the best fit line. Uncertainties include having to estimate the slope using only two points. One person might choose two different sets of points than someone else, yielding slightly different slopes. Of course, any differences in rounding could yield different results too. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:15:22 Briefly state what you think velocity is and how you think it is an example of a rate.
......!!!!!!!!...................................
RESPONSE --> Velocity is basically the same as speed except that it has emphasis on direction. from the equation d=rt, rate = distance/time This is basically the same equation as velocity, which is V=(change in distance)/(change in time) So, the equations are basically the same--velocity is a test of rate that is merely a bit more specific confidence assessment: 3
In this course t will generally stand for clock time and `dt for time interval. The symbol `d represents the capital Greek delta (the triangle symbol) and denotes 'change in ...', so `dt stands for 'change in t'.
Since d is used in `d to stand for 'change in', we generally won't use d to stand for any actual quantity (it would be confusing if we wanted to represent 'change in d' by '`dd').
We will use s or x to stand for position, so that `dx or `ds stands for the change in position.
What the equation v = d / t would calculate is actually the average speed or average velocity. We'll worry later about the difference between speed and velocity. Using `d for 'change in', t for clock time and s for position we use here the definition
vAve = `ds / `dt.
So for example if the ball travels 24 cm while the clock time changes from, say, 28.1 sec to 32.9 sec, we would observe the following:
`ds is the change in the position of the ball, which in this example is 24 cm.
`dt is the change in the clock time; if the TIMER program is triggered at clock times 28.1 sec and 31.7 sec, then the corresponding time interval will be the difference 31.7 sec - 28.1 sec = 3.6 sec.
So here we would have
vAve = `ds / `dt = 24 cm / 3.6 sec = 6.7 cm / sec.
.................................................
......!!!!!!!!...................................
20:15:35 ** 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 --> I understand. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:16:25 Given average speed and time interval how do you find distance moved?
......!!!!!!!!...................................
RESPONSE --> Average Speed=change in distance/change in time If given average speed and the time, one can solve backwards by multiplying the time by the average speed, yielding the distance moved. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:16:37 ** You multiply average speed * time interval to find distance moved. For example, 50 miles / hour * 3 hours = 150 miles. **
......!!!!!!!!...................................
RESPONSE --> I understand. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:17:47 Given average speed and distance moved how do you find the corresponding time interval?
......!!!!!!!!...................................
RESPONSE --> Avg speed=distance/time To find the time interval, one would multiply the distance by the average speed. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:18:56 ** 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. **
......!!!!!!!!...................................
RESPONSE --> Darn... I swear I meant that. Obviously, if one has the equation avg speed=distance/time, the progression would be as follows: average speed x time=distance time=distance/average speed I understood this before, but was silly and typed the wrong thing! I am fairly confident in this. self critique assessment: 3
.................................................
......!!!!!!!!...................................
20:19:19 Given time interval and distance moved how do you get average speed?
......!!!!!!!!...................................
RESPONSE --> One can divide the distance by the time interval. confidence assessment: 3
.................................................
......!!!!!!!!...................................
20:19:25 ** 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 --> self critique assessment: 3
.................................................
"