like activation energy is needed to be overcome before a chemical reaction can
occur, a force is needed to provide an initial ?jump-start?. From this I can
say that the force needed to just start an object moving is equal to the
static friction value for the surfaces. This accounts for the ?error? in
reading at the start, but still there is an error in the overall gradient of
the graph. Therefore I can conclude that friction must be acting at all times
during the experiment (after all there is a straight line which means
consistency throughout the testing). A rule that I can draw from this is that the
force needed to keep an object moving steadily (with constant velocity) on a
surface is equal to the dynamic friction value for the surface. With this I
can account for the unexpected gradient, but without doing further experiments
all they are at the moment are theories (see further experiments).Conclusion: Overall my results were not as I would have expected them to
be, but I hope I have provided some insight into the reasons for this. From my
research I know that Force is proportional to acceleration, even
though my graphs do not show this but the reasons that I have given tell me why
they do not show it. This is because I did not anticipate the force of friction
acting on the experiment and if I had I would have taken measures to make sure
that they did interfere with my final readings, or if they did then I would be
able to account for them and tell what the experiment would have been like if
there was a frictionless environment. Just like activation energy is needed to
be overcome before a chemical reaction can occur, a force is needed to provide
an initial ?jump-start?. From this I can say that the force needed to just
start an object moving is equal to the static friction value for the surfaces. This
accounts for some of the ?error? in my results, but still there is an error in
the overall readings. Therefore I can conclude that friction must be acting at
all times during the experiment (after all there is a straight line which means
consistency throughout the testing). A rule that I can draw from this is that the
force needed to keep an object moving steadily (with constant velocity) on a
surface is equal to the dynamic friction value for the surface. With this I
can account for the unexpected gradient, but without doing further experiments
all they are at the moment are theories (see further experiments). My
experiments have left me with some conclusions that I can make: As
increasing forces are applied to a constant mass, the acceleration of the
mass also increases (F = ma). The
force needed to just start an object moving is equal to the static
friction value for the surfaces. The
force needed to keep an object moving steadily (with constant velocity) on
a surface is equal to the dynamic friction value for the surface. Accuracy of Results and how they relate to my original
hypothesis: On the surface the accuracy of my results was quite poor, on
the other hand I have accounted for the discrepancies that occurred. The only
reason that my results are not very accurate is that I did not account for the
friction in the system and if I had I?m sure that my results would have
supported the hypothesis that I put forward, and in a light they actually do.
There are ways that I could re do my experiment so that friction would not be a
problem and I have included some of the ideas later on. Evaluation: Overall I was quite pleased with what I have managed to take
from the experiment, not so much the results but the information, which I have
been able to take out of it. Although my results were the readings that I
expected to take, I was very happy indeed with the procedure and the way in
which I still managed to maintain fair conditions for it to take place. This
leads me on to the point that, although I did not take friction into account,
my results were still congruent and they still followed the pattern that I
expected and still followed the trends of the graphs that I included in my
hypothesis and preliminary work. This is shown by the fact that my best fit
line on graph a, despite having an inaccurate gradient, had the points plotted
very close to it. Also my readings did not show up any anomalous results, which
again, fills me with confidence if I ever repeat the experiment in the future
that my results would be accurate. Of course if I did indeed do the
experiment again I would have to take friction into account. The way in
which I would suggest to overcome this would be to use an air track (picture
included). Instead of using the ticker-timer (over a period of 20 dots) to
measure the acceleration, a series of light gates would be used in the same
way. This would completely rid the experiment of friction though due to it
being an air track there would still be some resistance from air molecules.
Though this method, if one does not already own an air track, would be an
expensive method. Therefore another method that could be used would be to make
the beginning of the course elevated from the finish. This could be done using
a beam that is propped up at the start end with item such as textbooks or a car
jack. The right would be that which compensates exactly for the friction in the
experiment. The main aim of my experiment was
to basically prove the theory of F = ma. The bottom line is that I could
not prove the proportionality of Force and acceleration, and my graph did not prove this as the
line, although straight did not pass through the origin. I hope that my
reasoning for this is correct and if it then I would brand my whole experiment
a success. On the other hand I would like to do the experiment again and
implicate some of the changes that I have suggested, and I know that the school
does own an air track so the results would be a lot more accurate.Further Experiments: The next experiment that I would put into action would be
either of the ideas that I have suggested in the last section so that my
overall results would be closer to those that I had expected. Also I would keep
the force acting on the trolley constant but change the mass of the trolley
each time to further investigate the formula of F = ma.? ? ?????????????????????????????????