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.? **
The rate of flow will decrease at a decreasing rate as the headwater decreases
** Is the velocity of the water surface increasing, decreasing, etc.? **
The velocity of the water surface will decrease as well
** 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? **
The velocity of the water exiting the tube could be determined relative to headwater through culvert, head and weir flow calculations if enough data were known about the tube and its end condition. The diameter of the cylinder is irrelevant to flow through the tube as head pressure is directly related to depth irrelevant to reservoir size.
** Explain how we know that a change in velocity implies the action of a force: **
A change in velocity indicates a change in energy, thus force was applied. The force applied was gravity on the fluid in the reservoir.
** Does the depth seem to be changing at a regular rate, at a faster and faster rate, or at a slower and slower rate **
Depth is changing at a slower and slower rate
** What do you think a graph of depth vs. time would look like? **
Depth vs. time would be a decreasing curve - 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? **
Horiz. distance decreases vs time
** Does this distance change at an increasing, decreasing or steady rate? **
Horiz. distance decreases at a decreasing rate relative to the velocity in the tube.
** What do you think a graph of this horizontal distance vs. time would look like? **
It would be a decreasing curve - decreasing at a decreasing rate
** The contents of TIMER program as you submitted them: **
1 440.4688 440.4688
2 441.3438 .875
3 442.5 1.15625
4 443.6406 1.140625
5 444.8438 1.203125
6 446.1719 1.328125
7 447.5938 1.421875
8 449.1563 1.5625
9 450.9531 1.796875
10 453.0469 2.09375
11 455.5 2.453125
12 459.8281 4.328125
13 464.3438 4.515625
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
175 mm
160
146
131
117
101
87
71
56
40
24
8
0
** Your table for depth (in cm) vs clock time (in seconds) **
Clock Time Water level (cm)
0.00, 17.5
0.88, 16.0
2.03, 14.6
3.17, 13.1
4.38, 11.7
5.70, 10.1
7.13, 8.7
8.69, 7.1
10.48, 5.6
12.58, 4.0
15.03, 2.4
19.36, 0.8
23.88, 0.0
** 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 decreasing rate supporting my hypothesis above
** Your description of your depth vs. t graph: **
The curve of my graph decreases at a decreasing rate
** Your explanation and list of average average velocities: **
Average velocity is the distance traveled divided by the time interval
1.71
1.21
1.32
1.16
1.20
0.98
1.02
0.83
0.76
0.65
0.37
0.18
** The midpoints of your time intervals and how you obtained them: **
Interval midpoint clock time is the average of the clock times bracketing the interval
0.44
1.45
2.60
3.77
5.04
6.41
7.91
9.59
11.53
13.80
17.20
21.62
** Your table of average velocity of water surface vs. clock time: **
0.44, 1.71
1.45, 1.21
2.60, 1.32
3.77, 1.16
5.04, 1.20
6.41, 0.98
7.91, 1.02
9.59, 0.83
11.53, 0.76
13.80, 0.65
17.20, 0.37
21.62, 0.18
** Your description of your graph of average velocity vs clock time: **
CUrve decreases at a decreasing rate although it is less distinct where the curve lies from the data. Probably due to my poor eye-hand coordination.
Uncertainties are unavoidable in this experiment. The calculation of difference quotients magnifies uncertainties.
** Your explanation of how acceleration values were obtained: **
Acceleration is change in velocity over time
** Your acceleration vs clock time table: **
0.95, -0.50
2.03, 0.09
3.19, -0.13
4.41, 0.03
5.73, -0.16
7.16, 0.03
8.75, -0.11
10.56, -0.04
12.67, -0.05
15.50, -0.08
19.41, -0.04
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
Data is too scattered to give an accurate result but I believe it indicates a constant negative acceleration.
** **
0850~0945 = 55 min
&#Good responses. See my notes and let me know if you have questions. &#