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 think that the rate will increase.
** Is the velocity of the water surface increasing, decreasing, etc.? **
I would expect that it would increase.
** 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? **
Well, the water surface will drop depending on how fast the water exits. The diameter of the cyclinder is obviously much larger than the diameter of the hole, which means that only so much of the water in the cylinder can exit the hole at a time. If one knew the exact measurements of both the diameter of the cylinder and the diameter of the hole, then one could find the ratio of the two and could then use the ratio to help calculate the displacements with relation to time, and hence, the velocities of the water surface and of the exiting water.
** Explain how we know that a change in velocity implies the action of a force: **
We know that energy of movement is conserved, so unless a force was applied to make the water accelerate while exiting the hole then the water should be moving at the same velocity in the cylinder and in the hole.
** 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 rate seems to be changing at a faster and faster rate.
** What do you think a graph of depth vs. time would look like? **
The graph would have a negative slope and it would be decreasing at a decreasing rate.
This is the case; however if the depth was changing at a faster and faster rate (as you said in the previous question) this would not be so. The depth is in fact decreasing at a decreasing rate.
** 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? **
I am not underderstanding exactly what the horizontal distance is... If it is the stream that is leaving the cylinder then it decreases as time goes on.
** Does this distance change at an increasing, decreasing or steady rate? **
I would say that it changes at a steady rate.
** What do you think a graph of this horizontal distance vs. time would look like? **
I think it would be a relatively straight line with a negative slope.
It appears you have interpreted this part correctly.
** The contents of TIMER program as you submitted them: **
1 0 0
2 .90625 .90625
3 1.765625 .859375
4 2.671875 .90625
5 3.703125 1.03125
6 4.5 .796875
7 5.515625 1.015625
8 7.34375 1.828125
9 8.53125 1.1875
10 10.42188 1.890625
11 12.34375 1.921875
12 17.1875 4.84375
13 19.39063 2.203125
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
1.3
4.4
7.5
10.6
13.7
16.8
19.9
23
26.1
29.2
32.3
35.4
** Your table for depth (in cm) vs clock time (in seconds) **
0, 35.4
.90625, 32.3
.859375, 29.2
.90625, 26.1
1.03125, 23.0
.796875, 19.9
1.015625, 16.8
1.828125, 13.7
1.1875, 10.6
1.890625, 7.5
1.921875, 4.4
4.84375, 1.3
2.203125, 0
This appears to be a table of depth vs. time interval, not depth vs. clock time. Your clock times appear to run from 0 to nearly 20 seconds.
** Is the depth changing at a regular rate, at a faster and faster rate, or at a slower and slower rate? **
Until the water becomes even with the hole, the rate is changing at a faster and faster rate, which supports the conclusion that I drew above.
** Your description of your depth vs. t graph: **
The graph is increasing at an increasing rate, that it, the rate is getting faster on an already-positive slope.
** Your explanation and list of average average velocities: **
0
35.6
33.9
28.8
22.7
21.1
7.5
8.9
4.2
3.9
2.3
.26
0
I divided the water level distance from hole by the time it took the water to reach it.
The rate of depth change with respect to clock time is change in depth / change in clock time, i.e., the change in depth divided by the time interval.
** The midpoints of your time intervals and how you obtained them: **
0
.453125
.88609375
.88609375
.96875
.9140625
1.421875
1.8515625
1.8828125
1.90625
3.3828125
3.5432175
I added two adjacent times and then divided them by two to get the average between them. I did this for allt he time intervals.
That would be correct, but you appear to have used time intervals instead of clock times.
** Your table of average velocity of water surface vs. clock time: **
0, 35.6
.453125, 33.9
.88609375, 28.8
.88609375, 22.7
.96875, 21.1
.9140625, 7.5
1.421875, 7.5
1.8515625, 8.9
1.8828125, 4.2
1.90625, 3.9
3.3828125, .26
3.5432175, 0
** Your description of your graph of average velocity vs clock time: **
The slope of the graph is negative and, with the exception of a few poins that are sort of out there, the line is fairly straight--it doesn't indicate much concavity, hence not many rate changes.
** Your explanation of how acceleration values were obtained: **
I divided the changes in the velocities by the time intervals.
** Your acceleration vs clock time table: **
0, no acceleration?
.453125, 3.75
.88609375, 5.75
.88609375, 6.89
.96875, 1.65
.9140625, 14.88
1.421875, .98
1.8515625, 2.54
1.8828125, .16
1.90625, .84
3.3828125, .60
3.5432175, .07
acceleration is change in velocity / change in clock time; the clock times you will use are the midpoint clock times.
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
My data indicates that the accceleration is constant, and I believe that is about true.
Please see my notes and revise as indicated.