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 would decrease as water flows out of the cylinder because the pressure is decreasing in that there is less water and weight pushing downward in the cylinder.
** Is the velocity of the water surface increasing, decreasing, etc.? **
The velocity of the buoy would decrease because the rate of water flowing out of the cylinder is decreasing.
** 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 realizing that the velocity of the exiting water is going to increase or decrease the same amount as the velocity of the water surface increases or decreases.
** Explain how we know that a change in velocity implies the action of a force: **
F=m*a, a=F/m. For a to increase F must increase.
** 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 force that accelerates the water from inside the cylinder to the outside of the outflow hole is gravity. Gravity is pushing the water downward and therefore out of the hole. The depth is changing at a slower rate because we can see that the water flowing out of the hole in the third picture is not as strong as it was in the first picture.
** What do you think a graph of depth vs. time would look like? **
The graph would be decreasing at an increasing rate. The graph would be asymptotical to the x axis.
** 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 is decreasing as time goes on.
** Does this distance change at an increasing, decreasing or steady rate? **
This distance changes at an increasing rate.
** What do you think a graph of this horizontal distance vs. time would look like? **
The graph would be decreasing at an increasing rate.
** The contents of TIMER program as you submitted them: **
1 167.9531 167.9531
2 168.75 .796875
3 169.4219 .671875
4 170.6563 1.234375
5 171.75 1.09375
6 172.7813 1.03125
7 173.9219 1.140625
8 175 1.078125
9 176.0938 1.09375
10 177.3594 1.265625
11 178.7031 1.34375
12 180.0469 1.34375
13 181.3281 1.28125
14 182.8594 1.53125
15 184.5938 1.734375
16 186.3906 1.796875
17 188.2344 1.84375
18 190.3906 2.15625
19 192.625 2.234375
20 195.9219 3.296875
21 197.2656 1.34375
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
0
.7
1.4
2.1
2.8
3.5
4.2
4.9
5.6
6.3
7.0
7.7
8.4
9.1
9.8
10.5
11.2
11.9
12.6
13.3
14.0
** Your table for depth (in cm) vs clock time (in seconds) **
0, 14.0
.7969, 13.3
1.4688, 12.6
2.7032, 11.9
3.7969, 11.2
4.8282, 10.5
5.9688, 9.8
7.0469, 9.1
8.1407, 8.4
9.4063, 7.7
10.7500, 7.0
12.0938, 6.3
13.3750, 5.6
14.9063, 4.9
16.6407, 4.2
18.4375, 3.5
20.2813, 2.8
22.4375, 2.1
24.6719, 1.4
27.9688, .7
29.3125, .3
** Is the depth changing at a regular rate, at a faster and faster rate, or at a slower and slower rate? **
My data supports that the water velocity coming out of the outward hole is decreasing as time increases. The depth is changing at a slower and slower rate.
** Your description of your depth vs. t graph: **
My graph is decreasing at a decreasing rate. It is almost asymptotic to the x axis.
** Your explanation and list of average average velocities: **
.8784
1.0418
.5671
.6340
.6788
.6137
.6493
.6400
.5531
.5209
.5209
.5463
.4571
.4036
.3896
.3797
.3246
.3133
.2123
.2977
I found each time interval by dividing the distance in cm traveled in the time interval. For example I found the first number by dividing the ds=.7cm by the time interval=.7969 to get the average velocity=.8784cm/s.
** The midpoints of your time intervals and how you obtained them: **
.3985
1.1329
2.086
3.2501
4.3126
5.3985
6.5079
7.5938
8.7735
10.0782
11.4219
12.7344
14.1407
15.7735
17.4223
19.3594
21.3594
23.5547
26.3204
28.6407
I found the midpoints by averaging the previous clock time to the next clock time to get the midpoint of the interval.
** Your table of average velocity of water surface vs. clock time: **
.3985, .8784
1.1329, 1.0418
2.086, .5671
3.2501, .6340
4.3126, .6788
5.3985, .6137
6.5079, .6493
7.5938, .6400
8.7735, .5531
10.0782, .5209
11.4219, .5209
12.7344, .5463
14.1407, .4571
15.7735, .4036
17.4223, .3896
19.3594, .3797
21.3594, .3246
23.5547, .3133
26.3204, .2123
28.6407, .2977
** Your description of your graph of average velocity vs clock time: **
The graph is decreasing at an increasing rate. The best fit line is approaching the x axis at an almost asymptotic fashion.
** Your explanation of how acceleration values were obtained: **
2.2043
.9180
.2719
.1951
.1574
.1137
.0998
.0843
.0630
.0517
.0472
.0429
.0323
.0256
.0224
.0196
.0152
.0133
.0081
.0104
I took the velocity at the clock time and then divided it by the midpoint clock time to find the acceleration at that point.
This is not correct.
** Your acceleration vs clock time table: **
.3985, 2.2043
1.1329, .9180
2.086, .2719
3.2501, .1951
4.3126, .1574
5.3985, .1137
6.5079, .0998
7.5938, .0843
8.7735, .0630
10.0782, .0517
11.4219, .0472
12.7344, .0429
14.1407, .0323
15.7735, .0256
17.4223, .0224
19.3594, .0196
21.3594, .0152
23.5547, .0133
26.3204, .0104
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
My data indicates that the acceleration of the water surface is decreasing. I believe the acc of the water surface is actually decreasing.
** **
3 hours
Your accelerations are not calculated correctly.
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