Your work on flow experiment 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.?
decrease
Is the velocity of the water surface increasing, decreasing, etc.?
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?
as velocity of exiting water decreases so does surface water, as diameter of cylinder increases water velocity decreases, as exit hole diameter increases surface water velocity increases.
Explain how we know that a change in velocity implies the action of a force:
every reaction has a force behind it so for the velocity to change means that there must be a force causing it
Does the depth seem to be changing at a regular rate, at a faster and faster rate, or at a slower and slower rate
slower and slower
What do you think a graph of depth vs. time would look like?
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?
decreasing at a decreasing rate
Does this distance change at an increasing, decreasing or steady rate?
decreasing
What do you think a graph of this horizontal distance vs. time would look like?
decreasing at a decreasing rate
The contents of TIMER program as you submitted them:
1 64.95313 64.95313
2 67 2.046875
3 68.78125 1.78125
4 70.875 2.09375
5 72.875 2
6 75.21875 2.34375
7 77.75 2.53125
8 80.4375 2.6875
9 83.5625 3.125
10 87.3125 3.75
11 92.29688 4.984375
12 102.2188 9.921875
The vertical positions of the large marks as you reported them, relative to the center of the outflow hole
0
1.1875
1.9375
2.625
3.4375
4.25
5
5.625
6.375
7.125
7.875
8.5
Your table for depth (in cm) vs clock time (in seconds)
clock depth in inches
time
in seconds
0 8.5
2 7.875
3.8 7.125
5.9 6.375
7.9 5.625
10.2 5
12.8 4.25
15.4 3.4375
18.6 2.625
22.3 1.9375
27.3 1.1875
37.2 0
Is the depth changing at a regular rate, at a faster and faster rate, or at a slower and slower rate?
supports depth changes at a slower and slower rate
Your description of your depth vs. t graph:
decreases at a decreasing rate
Your explanation and list of average average velocities:
I did distance / time to find the beginning and ending velocities for each interval, then added the two together and divided by two. The first average was smaller than second because 0 was included
1.96875
2.90625
1.477754237
0.896266896
0.601110697
0.411113664
0.277622768
0.182171659
0.11400622
0.065190788
0.021749084
The midpoints of your time intervals and how you obtained them:
1
2.9
4.85
6.9
9.05
11.5
14.1
17
20.45
24.8
32.25
I took the start time and the stop time and added them together then divided by two
Your table of average velocity of water surface vs. clock time:
avg vel mid time
1.96875 1
2.90625 2.9
1.477754237 4.85
0.896266896 6.9
0.601110697 9.05
0.411113664 11.5
0.277622768 14.1
0.182171659 17
0.11400622 20.45
0.065190788 24.8
0.021749084 32.25
minor note on convention: ave vel. vs. mid time would have the columns reversed; independent variable goes in the first column
Your description of your graph of average velocity vs clock time:
decreasing at a decreasing rate
Your explanation of how acceleration values were obtained:
1.96875
1.002155172
0.304691595
0.129893753
0.066421072
0.035749014
0.019689558
0.01071598
0.005574876
0.002628661
0.00067439
I found the values by doing avg velocity by the time interval
Should have been change in velocity / change in clock time, i.e., change in velocity / time interval; not sure that's what you did.
Your acceleration vs clock time table:
mid time acceleration
1 1.96875
2.9 1.002155172
4.85 0.304691595
6.9 0.129893753
9.05 0.066421072
11.5 0.035749014
14.1 0.019689558
17 0.01071598
20.45 0.005574876
24.8 0.002628661
32.25 0.00067439
According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell?
acceleration is decreasing
yes, I actually think that the acceleration of the water surface is decreasing.
Theoretically, to the extent that viscosity has no effect, acceleration should be constant. This is because the differential equation v = dy/dt = sqrt( 2 g y), where g is acceleration of gravity, gives a general solution with y as a quadratic function of t. If y is a quadratic function of t, then v = dy/dt is a linear function and dv/dt is a constant function.
The differential equation is correct for a fluid with negligible viscosity and surface tension. These factors are in fact pretty much negligible in this experiment until near the end, where the flow slows to the point that other factors become more important.