Investigating Elasticity Flashcards
how would you carry out a pilot experiment to find out what size masses to use
- using an identical spring to the one you will be testing
- load it with the masses one at a time
- then record the force or weight and extension each time
- plot a force-extension graph and check that you get a nice straight line for at least the first 6 points
what should you do if the line on the force-extension graph curves too early in the pilot experiment
you should use smaller masses
what is the process of investigating elasticity
- measure the natural length of the spring
- add a mass to the spring and allow the spring to come to rest
- record the mass and measure the new length of the spring
- repeat the process until you have enough measurements
- plot a force-extension graph or your results
how should you measure the natural length of the spring
- with no force being applied to it
- and with a millimeter ruler clamped to the stand
how could you make your reading of the springs natural length and extension more accurate
- make sure you take the reading at eye level
- and add markers to the top and bottom of the spring
what is the measurement of the new length of the spring called after you have applied a mass
the extension, partly
what should you keep in mind when calculating the extension of the spring from your measurements after putting weights on it
- you should remember that the extension length is the length that the spring has increased by
- so you should be subtracting the total length of the spring after a mass has been applied from the natural length of the spring
- almost like you are calculating the distance travelled
when would your graph that you have drawn from your results only start to curve
when you exceed the limit of proportionality
why does a larger force cause a bigger extension of the spring when the graph beings to reach its limit of proportionality
because more work is needing to be done to cause a larger extension
what is the force that is doing work on the spring and what is this force equal to
- gravitational force
- and for elastic distortions, this force is equal to F = kx
how do you calculate the work done for a particular force or energy stored with your drawn graph
you calculate the section under your linear section of the force-extension graph up to that value of force
where is the elastic limit at in relation to the limit of proportionality
the elastic limit will always be at or beyond the limit of proportionality
what does the placement of the elastic limit and limit or proportionality mean in a linear relationship (especially about energy transfer)
- the distortion is always elastic
- which means that all the energy being transferred too the spring is stored in its elastic potential energy stores
when is the only time that the work done on a spring is equal to the energy that is stored in its elastic potential energy stores
when or as long as the spring is not stretched past its limit of proportionality
what formula do you use to work out the elastic potential energy stores, and therefore the work done, of a spring
- E = 1/2 * k * x^2
- energy transferred in stretching = 1/2 x spring constant x extension^2
