Mechanical Properties of a Meter Rule
AIM:
To investigate the mechanical properties of a meter rule via practical
experimentation.
INTRODUCTION
The mechanical properties of materials are its fitness and ability to resist applied or external forces. By external force is meant any force outside of a given piece of material which tends to deform it in any manner.
Knowledge of these properties is obtained through experimentation either in the employment of the wood in practice or by means of special testing apparatus in the laboratory. Owing to the wide range of variation in meter rulers it is necessary that a great number of tests are made and that so far as possible all disturbing factors be eliminated. For comparison of different kinds or materials a standard method of testing is necessary and the values must be expressed in some defined units. For these reasons laboratory experiments if properly conducted have many advantages over any other method.
One object of such investigation is to find unit values for strength and stiffness, etc. These, because of the complex structure of the materials, cannot have a constant value which will be exactly repeated in each test, even though no error be made. The most that can be accomplished is to find average values. On account of the great variability in strength of different specimens even from the same material and appearing to be alike, it is important to eliminate as far as possible all extraneous factors liable to influence the results of the tests.
The mechanical properties that I will consider are:
· Stiffness and elasticity
· Tensile strength
· ...
... middle of paper ...
... associated with nearly all measurements
and can never be completely eliminated.
* Friction between the hole and the nail as well as the table and
the rule. Sometimes the rule swung diagonally and might have
rubbed the table.
* Air resistance, I did the experiment near some windows and this
could have affected the experiment.
I could have carried out some further work on this investigation to
extend and broaden my results for example; I could have done more
lengths. I repeated the experiment several times and am happy with the
averages I got.
A more sophisticated experiment would definitely increase the accuracy
in the timings. Light gates would remove the error caused by reaction
times as they will accurately time the moment the rule passed over the
point to complete an oscillation.