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5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?
If the block had been coated in rubber the μ value would have increased because rubber would create more friction than the polished wood of the block. This would result in a greater friction force, which would in turn raise the value of μ.
I like the block picture........well done!
20/20

In the second trial, the frictional force was less than the first trial.
2. With your second trial, how did the coefficient of friction change compared to the first trial?
little less becuasebecause the frictional slightly less as well, howeverwhile the normal force remainedfremained the same. Overall, they were very similar.
3. Name at least two sources of experimental error that may have affected your results.
that could count for experiment error,have increased experimental error is that always pushed in a stright line, it sometimes went a little sideways whichwithout rotating. A slight spin on the block would have effectedaffected the distance traveled. The second thing to count on for experimentaland speed results of the trial. Another possible source of error is that friction was acting on the block as soon asdid not always in a straight line through the block was releasecd from someones hands, thisgate. This made it impossible to get exact measurements of distance traveled beyond the gate, which would effec tthe velocity. have skewed our data.
4. As the block is sliding to a halt, draw and label all the force vectors acting on the block:
{block.bmp}
5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?
the μ value would have decreasedincreased because rubber is a smoother surfacewould create more friction than the polished wood it is originally made out if. Ifof the surface wasblock. This would result in a smoother surface it was cause thegreater friction to be less,force, which would aslo cause the μ to be smaller. & Although the μ valus would have become smaller the weight and the net force would have remainedin turn raise the same.value of μ.

{block.bmp}
5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?
If the block had been coated in rubber the μ would have decreased because rubber is a smoother surface than the wood it is originally made out if. If the surface was a smoother surface it was cause the friction to be less, which would aslo cause the μ to be smaller. & Although the μ valus would have become smaller the weight and the net force would have remained the same.

Questions:
1. With your second trial, how did the force from friction change compared to the first trial?
In the second trial, the frictional force was less than the first trial.
2. With your second trial, how did the coefficient of friction change compared to the first trial?
The coefficient in the second trial was a little less becuase the frictional force was slightly less as well, however the normal force remainedf the same.
3. Name at least two sources of experimental error that may have affected your results.
{file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image001.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image002.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image003.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image004.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image005.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image006.gif} 4.The first thing that could count for experiment error, is that the block was not always pushed in a stright line, it sometimes went a little sideways which would have effected the distance traveled. The second thing to count on for experimental error is that friction was acting on the block as soon as the block was releasecd from someones hands, this would effec tthe velocity.
4. As the the block:
{block.bmp}
5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?

0.27
0.24
Questions:Calculations:
1. With your second trial, how didFind the force from friction change compared tospeed as the first trial?block slides through the photogate.
velocity=(delta)x/(delta)t
V= 0.076 meters/0.066 seconds
V= 1.15 meters/second
2. With your second trial, how didConcider the coefficientprevious speed you found as the initial speed of friction change comparedthe sliding block. Use Vi and the distance it slid to find the acceleration of the first trial?block.
V(final)^2= V(inital)^2 + 2a(distance)
0= 1.15 + 2a(.225 m)
-1.3225=.506a
-2.61 m/s/s = a
3. Name at least two sources of experimental error that may have affected your results.Using the previous acceleration, find the net force acting on the sliding black. This will be our frictional force.
F(net)=ma
F(f)=ma
F(f)=(.131 kg)(-2.61 m/s/s)
F(f)= -.0342 N
4. Useing our frictional force and normal force, find the coefficient of kinetic friction between the two surfaces.
Fw=Wt=ma
(.131 kg)(9.8m/s/s)= -1.28 N
Mm= Frictional Force/Net Froce
Kinetic Force= -.342 N/-1.28 =
0.267
Questions:
1. With your second trial, how did the force from friction change compared to the first trial?
2. With your second trial, how did the coefficient of friction change compared to the first trial?
3. Name at least two sources of experimental error that may have affected your results.
{file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image001.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image002.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image003.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image004.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image005.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image006.gif} 4. As the block is sliding to a halt, draw and label all the force vectors acting on the block:
5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?

Data Table:
Shaded areas indicate direct measurements.
Non shaded areas are calculated values.
Initial trial
Second trial
2. With your second trial, how did the coefficient of friction change compared to the first trial?
V(final)^2= V(inital)^2 + 2a(distance)
0= 1.15 + 2a(.225 m)
0= 1.3225 + .506a
-1.3225=.506a
-2.61 m/s/s = a
3. Name at least two sources of experimental error that may have affected your results.
F(net)=ma
F(f)=ma
F(f)=(.131 kg)(-2.61 m/s/s)
F(f)= -.0342 N
{file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image001.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image002.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image003.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image004.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image005.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image006.gif} 4. As the block is sliding to a halt, draw and label all the force vectors acting on the block:
5. If instead, the block was coated with a rubber surface, how do you think your μ value would change?

Friction between the cart and the track may have slowed the cart's acceleration.
The string connecting the cart and hanging mass may have had a tension force that affected the results.
Tension does not affect results......tension pulling hanging mass up would cancel out the same tension value pulling the cart across.
14/15
3. If you add more mass to the hanging end, what effect would that have on the acceleration?
The acceleration would be greater because the weight of the hanging mass would therefore increase.

V= 1.15 meters/second
2. With your second trial, how did the coefficient of friction change compared to the first trial?
V(inital)^2 + 2aV(delta)2a(distance)
3. Name at least two sources of experimental error that may have affected your results.
{file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image001.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image002.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image003.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image004.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image005.gif} {file:///C:%5CDOCUME%7E1%5C2011RO%7E2%5CLOCALS%7E1%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_image006.gif} 4. As the block is sliding to a halt, draw and label all the force vectors acting on the block: