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 as water flows from the cylindar. The water will at first rush out of the holes, but as the water level decreases so will the rate of flow.
** Is the velocity of the water surface increasing, decreasing, etc.? **
I would expect the velocity of the buoy 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? **
You could determine the velocity of the water surface by taking the velocity of the exiting water through the diameter of the hole and compare it to the decreasin water level of the water in the cylindar to determine the velocity.
** Explain how we know that a change in velocity implies the action of a force: **
A change in velocity implies a action of force, because some force caused the velocity to either speed up or slow down.
** Does the depth seem to be changing at a regular rate, at a faster and faster rate, or at a slower and slower rate **
Gravity pulling the water out of the hole and onto the ground. The depth seems to slow down.
** What do you think a graph of depth vs. time would look like? **
It would show that as the depth decreased the time of exit increased.
** 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 decreases as time goes on.
** Does this distance change at an increasing, decreasing or steady rate? **
The distance changes at a steady rate.
** What do you think a graph of this horizontal distance vs. time would look like? **
The horizontal distance would decrease as the time increased.
** The contents of TIMER program as you submitted them: **
1 149.1406 149.1406
2 150.1719 1.03125
3 150.5 .328125
4 150.9375 .4375
5 151.6094 .671875
6 152.5938 .984375
7 153.7031 1.109375
8 155.1719 1.46875
9 157.5 2.328125
10 159.9375 2.4375
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
0 cm
0.5 cm
2.0 cm
3.5 cm
5.0 cm
6.5 cm
8.0 cm
9.5 cm
11.0 cm
12.5 cm
** Your table for depth (in cm) vs clock time (in seconds) **
0, 12.5
1.03, 11
.33, 9.5
.44, 8
.67, 6.5
.98, 5
1.10, 3
1.47, 2
2,32, .5
2.44, 0
It looks like you are reporting time intervals rather than clock time. Clock time is the total time which elapsed from the beginning of the flow to each depth, not the time which has elapsed since the preceding depth measurement.
** 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 shows the increased slowing of the time for the water to exit as it goes further down the cylindar.
** Your explanation and list of average average velocities: **
I took the cahnge in distance ('dx) and divided it by the cahnge in time ('dt).
1.45cm/s
2.15cm/s
13.6cm/s
6.52cm/s
4.83cm/s
12.5cm/s
4.05cm/s
1.76cm/s
12.5cm/s
These results are based on erroneous clock times and will need to be revised, as will all subsequent results based on them.
** The midpoints of your time intervals and how you obtained them: **
I took the summ of the two time intervals and divided them by 2.
.515 s.
.865 s.
.405 s.
.170 s.
.270 s.
.215 s.
.245 s.
.610 s.
.485 s.
** Your table of average velocity of water surface vs. clock time: **
.515, 1.45
.865, 2.15
.405, 13.63
.170, 6.52
.270, 4.83
.215, 12.5
.245, 4.05
.610, 1.76
.485, 4.05
** Your description of your graph of average velocity vs clock time: **
The points on the graph are scattered throughout and do not show any particular pattern.
** Your explanation of how acceleration values were obtained: **
I obtained my acceleration values by taking the change in velocity and dividing it by the change in time.
** Your acceleration vs clock time table: **
.515, 2.81
.865, 2.48
.405, 33.6
.170, 38.5
.270, 17.8
.215, 58.1
.245, 16.5
.610, 2.88
.485, 8.35
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
The data indicates that my results are inconclusive.
I think the acceleration of the water surface is decreasing.
Please submit a revision as indicated above. Mark your revisions with &&&&; questions are also welcome.