Forces and Elasticity Flashcards
what happens when you apply a force to an object?
you may cause it to bend, compress, stretch
How do you apply a force to an object?
By using more than one force - otherwise the object would simply move in the direction of the applied force instead of changing shape
elastically distorted
an object that can go back to its original shape and length after the force has been removed
inelastically distorted
an object that doesn’t return to its normal shape or length after the force has been removed
what is the elastic limit?
the point where the objects stop distorting elastically and starts distorting inelastically
when is work done?
when a force compresses or stretches an object and causes energy to be transferred to the elastic potential energy store of the object
what kind of relationship does the extension of a spring and load of a spring have?
they are directionally proportional to each other so f x X
this means that they have a linear relationship
extension and load/force equation
Force =. spring constant x extension
what does the spring constant depend on?
the material you are stretching
what does it mean when a force extension graph has a curve?
The curve is the maximum force - this shows that extension is no longer proportional to force so the relationship is non -linear - limit of proportionality
what is the point called where it starts to curve off in a force extension graph?
limit of proportionality
how do you find the energy in the elastic potential energy store for a graph with a linear relationship?
energy transferred = 1/2 x spring constant x extension(squared)
what are the units for spring constant?
N/m
Linear graph in force extension graphs
straight line through (0,0)
directionally proportional
non linear graph in force extension graphs
straight line to curve
no longer directionally proportional
method for investigating elasticity
measure the natural length of spring with ruler
add a mass to spring and allow spring to stop
record mass and measure new length
repeat until 600g
plot a force-extension graph
what is the extension of the investigating elasticity?
the new length of the spring when you add a mass
what should you find for a larger force in the elasticity investigation?
what force is doing the work?
a larger force causes a bigger extension
- more work needing to be done to cause a larger extension
force doing the work is GPE
how do you find the work done for a particular force or energy store?
by calculating the area under the linear section of your graph up to the value of the force
