flow experiment

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.

Is the velocity of the water surface increasing, decreasing, etc.?

I would expect the velocity of the buoy to decrease also.

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?

If you have the diameter of the cylinder and the diameter of the hole, and the velocity of the exiting water, you could use the velocity of the exiting water and the diameter of the hole to determine the volume of the liguid exiting the cylinder. Then you could use that data combined withe the diameter of the cylinder to determine the velocity of the water surface.

Explain how we know that a change in velocity implies the action of a force:

I'm not sure what you mean.

Gravity is the only force I can think of.

that is the source of the force. The answer to the question, however, is Newton's Second Law. If you have a mass with nonzero acceleration, you have a nonzero net 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

It's hard to tell in the pictures, but I think that the rate of change would slow as the column of liquid decreases.

What do you think a graph of depth vs. time would look like?

I think that it would decrease 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?

It decreases

Does this distance change at an increasing, decreasing or steady rate?

It's hard to tell. I think it would decrease at a increasing rate

What do you think a graph of this horizontal distance vs. time would look like?

It would decrease at a increasing rate.

The contents of TIMER program as you submitted them:

1 226.4531 226.4531

2 228.8125 2.359375

3 231.2344 2.421875

4 233.8438 2.609375

5 236.7188 2.875

6 239.5938 2.875

7 242.7813 3.1875

8 246.3594 3.578125

9 250.4844 4.125

10 256.0781 5.59375

11 263.3906 7.3125

12 274.0156 10.625

The vertical positions of the large marks as you reported them, relative to the center of the outflow hole

.6cm

2.6cm

4.6cm

6.5cm

8.5cm

10.4cm

12.3cm

14.2cm

16.1cm

17.9cm

19.8cm

21.6cm

Your table for depth (in cm) vs clock time (in seconds)

0,21.6

2.36,19.8

4.78,17.9

7.39,16.1

10.26,14.2

13.14,12.3

16.33,10.4

19.90,8.5

24.03,6.5

29.62,4.6

36.94,2.6

47.56,.6

Is the depth changing at a regular rate, at a faster and faster rate, or at a slower and slower rate?

Yes the data supports the answer I gave. The depth changes at a slower and slower rate.

Your description of your depth vs. t graph:

The graph decreases at a decreasing rate.

Meaning the velocity in which the water level changes slowes over time.

Your explanation and list of average average velocities:

I divided the distance of the change in water level by the time in which the event occured. The produced an average velocity in cm/s.

.76

.78

.68

.66

.66

.59

.53

.48

.33

.27

.18

The midpoints of your time intervals and how you obtained them:

divide each time interval by 2 then added back to th original time.

1.18

3.57

6.085

8.825

11.695

14.730

18.115

21.96

26.825

33.275

42.250

Your table of average velocity of water surface vs. clock time:

1.18,.76

3.57,.78

6.085,.68

8.825,.66

11.695,.66

14.73,.59

18.115,.53

21.96,.48

26.825,.33

33.275,.27

42.250,.18

Your description of your graph of average velocity vs clock time:

My graph is a little funny looking but it seems to be decreasing at a steady rate.

There will be some 'noise' in your data, but the points should indeed indicate a linear trend.

Your explanation of how acceleration values were obtained:

average acceleration is obtianed by taking the change in velocity and dividng it by the time it took to make the change. cm/s^2 My data is a little flawed, but I can see a pattern.

.644

.008

.039

.007

0

.023

.017

.013

.030

.009

.010

Your acceleration vs clock time table:

1.18,.644

3.57,.008

6.085,.039

8.825,.007

11.695,0

14.73,.023

18.115,.017

21.96,.013

26.825,030

33.275,.009

42.250,010

According to the evidence here, is acceleration increasing, decreasing, staying the same or is in not possible to tell?

My results are inconclusive, but the look as though the acceleration is decreasing.

I think the the acceleration of the surface is decreasing as time increases.

Good work.

It's difficult to tell because of the 'noise' in the data. However if your velocity vs. clock time is pretty nearly linear, this is a good indication that acceleration is pretty nearly constant.