Phy 232
Your 'flow experiment' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** Your initial message (if any): **
** Is flow rate increasing, decreasing, etc.? **
I would expect the rate of flow to decrease.
** Is the velocity of the water surface increasing, decreasing, etc.? **
I would expect the velocity to decrease.
** How would the velocity of the water surface, the velocity of the exiting water, the diameter of the cylinder and the diameter of the hole be interrelated? **
I would assume the velocity at the water surface and exiting water are the same. The velocity of the water surface can be calculated from the depth of the water and the time. To find the velocity, find the change in depth and divide this by the change in time.
** Explain how we know that a change in velocity implies the action of a force: **
If there was no change in velocity, that means a constant force is acting on the water. If the water is moving slower or faster, that means it is either decelerating or accelerating. However, both means that there is a change in force.
** Does the depth seem to be changing at a regular rate, at a faster and faster rate, or at a slower and slower rate **
The depth appears to be changing at a slower and slower rate.
** What do you think a graph of depth vs. time would look like? **
I think the graph would show a steep change in depth over time but then level off and eventually the depth would remain 0.
** Does the horizontal distance (the distance to the right, ignoring the up and down distance) traveled by the stream increase or decrease as time goes on? **
The horizontal distance appears to decrease.
** Does this distance change at an increasing, decreasing or steady rate? **
It appears to decreasing rate.
** What do you think a graph of this horizontal distance vs. time would look like? **
This would show a curve of decreasing horizontal distance and be more steep at the beginning of the graph but then have a smaller slope.
** The contents of TIMER program as you submitted them: **
1 207.375 207.375
2 210.0469 2.671875
3 213.4531 3.40625
4 217.1406 3.6875
5 220.8125 3.671875
6 225.1094 4.296875
7 229.9219 4.8125
8 235.4063 5.484375
9 241.75 6.34375
10 250.2344 8.484375
11 283.0469 32.8125
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
24.5
23
21.5
20
18.5
17
15.5
14
12.5
11
9.5
** Your table for depth (in cm) vs clock time (in seconds) **
0 24.5
2.671875 23
6.078125 21.5
9.765625 20
13.4375 18.5
17.734375 17
22.546875 15.5
28.03125 14
34.375 12.5
42.859375 11
85.671875 9.5
** Is the depth changing at a regular rate, at a faster and faster rate, or at a slower and slower rate? **
The depth is changing at a slower and slower rate.
** Your description of your depth vs. t graph: **
The graph starts out with a steep slope as time increases, however then the slope becomes much less steep and appears to almost level out.
** Your explanation and list of average average velocities: **
The velocities are in units of m/s. I calculated the velocities the same way I would a slope. I found the change in depth (or y units) for each interval and then divided by the change in time (or x units)
-0.561
-0.440
-0.407
-0.409
-0.349
-0.312
-0.274
-0.236
-0.177
-0.035
** The midpoints of your time intervals and how you obtained them: **
1.34
4.38
7.92
11.60
15.59
20.14
25.29
31.20
38.62
64.27
I obtained the midpoint of each time interval by adding what the interval was between and dividing by 2. For example the first time interval was between 0 and 2.671875. I added these 2 numbers together and divided by 2, reaching 1.34 as my midpoint (I rounded to 3 sig figs).
** Your table of average velocity of water surface vs. clock time: **
-0.081,1.34
-0.022,4.38
0.001,7.92
-0.040,11.60
-0.025,15.59
-0.025,20.14
-0.025,25.29
-0.040,31.20
-0.095,38.62
-0.023,64.27
good, but your columns are reversed; y vs. x has x in the first column
** Your description of your graph of average velocity vs clock time: **
The graph has no clear pattern. It increases between the time intervals of 1.34 to 7.92, but then decreases between 7.92 and 11.60 then increases again. It continues a pattern of increasing and decreasing throughout the graph. There is no real clear pattern.
** Your explanation of how acceleration values were obtained: **
The acceleration is in units of m^2/s. I calculated the acceleration the same way I would a slope. I found the change in velocity (or y units) for each interval and then divided by the change in time (or x units)
0.019183378
0.006638386
-0.011078967
0.003683912
-0.000114379
0.000146707
-0.002548339
-0.007382499
0.002773985
-0.000363455
The acceleration
** Your acceleration vs clock time table: **
0.019183378,1.34
0.006638386,4.38
-0.011078967,7.92
0.003683912,11.60
-0.000114379,15.59
0.000146707,20.14
-0.002548339,25.29
-0.007382499,31.20
0.002773985,38.62
-0.000363455,64.27
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
The data does not indicate how the acceleration is changing. I would say the results are inconclusive.
I think the acceleration is actually decreasing.
** **
about an hour
&#Good responses. See my notes and let me know if you have questions. &#