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, and at first, the water pours out with a stronger force because there is so much water pushing the water at the bottom out of the hole. As the pressure decreases on the water at the bottom as more water pours out, the rate of flow decreases.
** Is the velocity of the water surface increasing, decreasing, etc.? **
I would expect the velocity of the water surface to increase as water flows out of the cylinder, because the pressure behind the water gets less as more water flows out of the hole.
** 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? **
A1 * v1 = A2 * v2 then you could solve for v2, which would be the velocity of the water surface. A2 is the area of water surface, which is also equal to the diameter of the cylinder. A1 is the diameter of the hole. v1 is the velcity of the exiting water.
** Explain how we know that a change in velocity implies the action of a force: **
Bernoulli's Principle states that where velocity is low, pressure is high, and where velocity is high, pressure is low. This change in velocity definately implies the action of a 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 seems to be changing at an increasing rate.
** What do you think a graph of depth vs. time would look like? **
It would decrease at an increasing rate from left to right as time passes.
** 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? **
It increases? I say this because the line starts at a higher number on the y-axis when it is at zero on the x-axis. But as time passes, the number on the y-axis gets increasingly lower, so the line is extending outward as it is going down.
** Does this distance change at an increasing, decreasing or steady rate? **
I believe the distance changes at in increasing rate, because as time passes, the distance goes down faster and faster until it reaches zero.
** What do you think a graph of this horizontal distance vs. time would look like? **
I think it would decrease from left to right as time passed.
** The contents of TIMER program as you submitted them: **
1 3318.625 3318.625
2 3319.578 .953125
3 3320.625 1.046875
4 3321.75 1.125
5 3322.844 1.09375
6 3324.047 1.203125
7 3325.266 1.21875
8 3326.469 1.203125
9 3327.594 1.125
10 3328.859 1.265625
11 3329.984 1.125
12 3331.453 1.46875
13 3332.688 1.234375
14 3334.016 1.328125
15 3335.328 1.3125
16 3336.625 1.296875
17 3338.078 1.453125
18 3339.453 1.375
19 3340.922 1.46875
20 3342.469 1.546875
21 3343.922 1.453125
22 3345.391 1.46875
23 3347.125 1.734375
24 3348.625 1.5
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
0.6
1.4
2.2
3.0
3.8
4.6
5.4
6.1
6.9
7.7
8.4
9.1
9.9
10.6
11.4
12.1
12.9
13.6
14.4
15.1
15.8
16.6
17.3
** Your table for depth (in cm) vs clock time (in seconds) **
0.00, 17.3
0.95, 16.6
2.00, 15.8
3.13, 15.1
4.22, 14.4
5.42, 13.6
6.64, 12.9
7.84, 12.1
8.97, 11.4
10.23, 10.6
11.36, 9.9
12.83, 9.1
14.06, 8.4
15.39, 7.7
16.70, 6.9
18.00, 6.1
19.45, 5.4
20.83, 4.6
22.30, 3.8
23.84, 3
25.30, 2.2
26.77, 1.4
28.50, 0.6
30.00, 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 regular rate. The graph is pretty much a straight line decreasing at a constant rate from left to right. So this data supports my answers to a point but contradicts when I said the line was decreasing at an increasing rate.
** Your description of your depth vs. t graph: **
The graph is decreasing at a constant rate from left to right as time passes.
** Your explanation and list of average average velocities: **
The average velocity is the displacement divided by the time elapsed. This is also found by dividing the (final position - initial position) by the time elapsed.
.734
.764
.622
.640
.665
.574
.665
.622
.632
.622
.545
.567
.527
.609
.617
.482
.582
.545
.517
.551
.545
.461
.400
** The midpoints of your time intervals and how you obtained them: **
0.475
1.475
2.565
3.675
4.82
6.03
7.24
8.405
9.6
10.795
10.965
13.445
14.725
16.045
17.35
18.725
20.14
21.565
23.07
24.57
26.035
27.635
29.25
I obtained these midpoints by subtracting one midpoint from another, then dividing that number by two and adding that number back to the lowest time interval to get the midpoint between the two time intervals.
** Your table of average velocity of water surface vs. clock time: **
0.475, 0.734
1.475, 0.764
2.565, 0.622
3.675, 0.64
4.82, 0.665
6.03, 0.574
7.24, 0.665
8.405, 0.622
9.6, 0.632
10.795, 0.622
10.965, 0.545
13.445, 0.567
14.725, 0.527
16.045, 0.609
17.35, 0.617
18.725, 0.482
20.14, 0.582
21.565, 0.545
23.07, 0.517
24.57, 0.551
26.035, 0.545
27.635, 0.461
29.25, 0.4
** Your description of your graph of average velocity vs clock time: **
The graph is generally decreasing at a constant rate from left to right as time passes. However a best fit line must be used in this situation because the points fluctuate up and down but move in a generally decreasing form.
** Your explanation of how acceleration values were obtained: **
I obtained my acceleration values by subtracting two velocities from eachother and then dividing by the amount of time between the two intervals to get the average acceleration which is the change in velocity divided by the change in time.
** Your acceleration vs clock time table: **
0.975, 0.03
2.02, -0.13
3.105, 0.0162
4.2475, 0.0218
5.425, -0.0752
6.635, 0.0752
7.8225, -0.0369
9.0025, 0.00837
10.1975, -0.00837
10.88, -0.453
12.205, 0.00887
14.085, -0.03125
15.385, 0.06212
16.6975, 0.00613
18.0375, -0.09818
19.4325, 0.07067
20.8525, -0.02596
22.3175, -0.0186
23.82, 0.02267
25.3025, -0.0041
26.835, -0.0525
28.4425, -0.03801
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
The acceleration is inconclusive because the points are all over the place. I think the acceleration is probably constant because it is the change in velocity over time and the velocity was pretty constant throughout the experiment, so I am assuming the acceration is pretty constant as well.
Excellent results, and I agree with your interpretation. The inconsistencies in your accelerations are due to deterioration of difference quotients; the relatively constant slope of your v vs. t graph is a good indication that acceleration is constant.