Winkler Method for Dissolved Oxygen AnalysisFull description
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Lab ReportFull description
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PhysiologyFull description
Plant and Animal Cells
EXPERIMENT 2
Introduction
A flywheel flywheel is a large disc disc with a certain certain mass and dimension dimension depending depending on the purpose purpose that rotates freely and stores kinetic energy. The flywheel is essentially a mechanical battery as it stores the energy and then discharges. A flywheel with greater mass and dimensions will have bigger power storage. An example of of a flywheel is attached attached to the crankshaft crankshaft in a car engine engine which stores the energy of the firing pistons and then discharges to allow for a constant smooth power output. The use of the fly wheel cuts down on the vibrations of the engine. A simpler use of a flywheel is in a toy car where a large flywheel is connected to the driven wheels and when the car is pushed forward the flywheel stores the initial acceleration and then uses this energy to propel the car after it is released. Another Another example of the use of a flywheel is in uninterrupted power supply systems where the flywheel is used instead of a battery. Advantages of of using the fly wheel wheel in this situation would would cut down on on maintenance and and have less impact on the environment environment as it is made of harmless materials. The flywheel does have disadvantages disadvantages as it can be very expensive and when it overloads it can shatter The main objective of this experiment is to find the t he relationship between time and displacement. Theory
Considering the forces acting on the falling mass (M and !ewton"s second law of motion#
Mg − T = Ma
$.
%or the flywheel the tension# T provides an acceleration tor&ue for the flywheel# '. 1
I = M f R
here
Tr = I α
2
2
) is the polar moment of inertia for the fly wheel and * is the angular acceleration. Assuming that the string string does not stretch stretch then +. ,ubstitute e&uations ' and + into $ to obtain Mg
Ia
−
r
2
Ma
=
a
=
αr
g
a= .
1+
I M r
2
Assuming the acceleration a is constant from release# time taken can be predicted for a specific fall s. !ow using an e&uation of motion and rearranging it when u/0. 1
2
s =ut + a t 2
1
2
s = a t 2
2
1.
t =
2s
a
2
!ow the e&uation is rearranged for
t we can sub in e&uation to derive an e&uation t. 2
2.
Apparatus
%igure $ All the dimensions in figure $ are in mm
t =
2s
g
( 1+
I M r
2
)
)n this experiment a flywheel with diameter +00mm and thickness of 3mm was used. And a weight of $! was attached to the shaft of dimensions $$+mm length and +2mm diameter. The wall at the back of the flywheel had lines spaced at intervals of 0.'m so that readings could be taken at each. A stopwatch was also used in this experiment to take the time taken for the mass to fall. Procedure
The mass of $! attached to the shaft and flywheel was aligned to the 0.$ m marking on the wall this was difficult since the weight wasn"t close to the wall so this could have caused inaccurate readings. )t was then dropped and allowed to accelerate from 0 m to 0.'m and the readings from stopwatches were taken. This was repeated for each interval of 0.'m up to 4m Results
5isplacement (m 0 0.' 0. 0.2 0.4
6esults (s 0 3.0 $$.0 $'.43 $1.'1
0 3.13 $$.$' $'.9 $1.+
0 3.3 $0.9 $'.4 $1.$4
Mean of results 0 3.1 $$.00 $'.49 $1.'$
0 3.+ $0.90 $'.9$ $1.02
7ncertaintie s (8s 0 0.131 0.011 0.0'1 0.030
Table 1
Table one shows the results from the experiment the uncertainties where calculated by,
maximumreading− minimumreading Random uncertainty = number of readings Displaceme nt (m) Results for 2
t
0
0.2
0.
0.!
0."
(s)
Table 2
Table 2 shows the theoretical results for the #ywheel. They were calculated usin$ the method below 2
