PHY202
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 the water flows from the container.
** Is the velocity of the water surface increasing, decreasing, etc.? **
I would expect the velocity of the water surface 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? **
The velcoity of the water surface is dependent on the diameter of the cylinder and the diameter of the hole and is directly proportional to the velocity of the exiting water. The velocity of the water surface = (velcoity of the exiting water/diameter of hole)*diameter of cylinder.
** Explain how we know that a change in velocity implies the action of a force: **
acceleration = force/mass and since average acceleration = change in velocity / change in clock time then the change in velocity would imply a change in force. More force would increase the velocity, less force would decrease velocity.
** 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 a slower and slower rate.
** What do you think a graph of depth vs. time would look like? **
The line of the graph would travel from the top left down toward the right with the slope decreasing between each point more and more.
** 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 traveled by the stream decreases as time goes by.
** Does this distance change at an increasing, decreasing or steady rate? **
The distance changes at a decreasing rate.
** What do you think a graph of this horizontal distance vs. time would look like? **
The line of the graph would travel from the top left down toward the right with the slope decreasing between each point more and more.
** The contents of TIMER program as you submitted them: **
1 596.4453 596.4453
2 598.5234 2.078125
3 600.5234 2
4 602.9141 2.390625
5 605.3828 2.46875
6 607.9297 2.546875
7 610.9766 3.046875
8 613.8828 2.90625
9 617.2109 3.328125
10 621.7422 4.53125
11 627.1641 5.421875
12 634.8516 7.6875
** The vertical positions of the large marks as you reported them, relative to the center of the outflow hole **
0.9
2.45
4.00
5.55
7.05
8.55
10.05
11.50
13.00
14.45
15.90
** Your table for depth (in cm) vs clock time (in seconds) **
Clock time (in seconds measured from first reading) Depth of water (in cm, measured from the hole)
0 15.9
2.08 14.45
4.08 13.0
6.47 11.5
8.94 10.05
11.48 8.55
14.53 7.05
17.44 5.55
20.76 4.0
25.30 2.45
30.72 0.9
38.41 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 slower and slower rate.
** Your description of your depth vs. t graph: **
The line of the graph travels from the top left down toward the right with the slope decreasing between each point more and more.
** Your explanation and list of average average velocities: **
I obtained the average velocities using avg velocity = 'ds/'dt.
average velocity
0
0.697115385
0.725
0.627615063
0.587044534
0.590551181
0.491803279
0.515463918
0.46686747
0.341409692
0.28597786
0.117035111
** The midpoints of your time intervals and how you obtained them: **
0
1.04
3.08
5.275
7.705
10.21
13.005
15.985
19.1
23.03
28.01
34.565
** Your table of average velocity of water surface vs. clock time: **
clock time midpoint, average velocity
0, 0
1.04, 0.697115385
3.08, 0.725
5.275,0.627615063
7.705, 0.587044534
10.21, 0.590551181
13.005, 0.491803279
15.985, 0.515463918
19.1, 0.46686747
23.03, 0.341409692
28.01, 0.28597786
34.565, 0.117035111
** Your description of your graph of average velocity vs clock time: **
The jagged line of the graph travels from the top left down toward the right with the slope increasing or decreasing between each point. The points are closer together at the top left and move farther apart as the line progresses to the bottom right.
The jagged line is jagged simply because it is following your uncertainties around. The actual behavior is either a straight line or a smooth curve. Can you describe the straight line or smooth curve that best fits your data?
** Your explanation of how acceleration values were obtained: **
avg accel water surface
0
0.670303254
0.013668929
0.044366714
0.016695691
0.001399859
0.035330198
0.007939812
0.015600786
0.031923099
0.01113089
0.025773112
To obtain average acceleration i used avg acceleration = 'dv/'dt
** Your acceleration vs clock time table: **
clock time midpoint, avg accel water surface
0, 0
0.52,0.670303254
2.06, 0.013668929
4.1775, 0.044366714
6.49, 0.016695691
8.9575, 0.001399859
11.6075, 0.035330198
14.495, 0.007939812
17.5425,0.015600786
21.065, 0.031923099
25.52, 0.01113089
31.2875, 0.025773112
** According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell? **
The data indicates the acceleration of the water surface is constant.
I think the acceleration of the water surface is constant.
** **
3hours
The acceleration of the water surface should indeed be constant.
The jaggedness of the one graph you describe is the result of the deterioration of difference quotients, as in that lab exercise.
See my note and send me a description of that graph, along with a copy of your velocity versus midpoint clock time table.