P2 - 5.5 Elasticity, Spring Constant + Hooke's Law Flashcards
When apply a force on an object what 3 effects could it have on the object
- compress
- stretch
- bend
What is an example of a very elastic object
- spring
- elastic band
To get an object to stay still what do we need to do in terms of force
Apply more than one force
What is the term used when an object has changed shaped
Deformed
What is meant when we say an object is deformed
It has been changed/altered in terms of its shape
What are the 2 main types of deformation
- elastic
- inelastic
What type of deformation would a spring be if when stretched it returns to its normal state
Elastic
What type of deformation would it be if an object didn’t return to its original shape
Inelastic
What is inelastic deformation also known as
Plastic deformation
What is extension
The increase in length of a spring when its stretched
How can we test how much weight a spring can take before become an inelastic deformation
By hanging the spring (creating a downwards force) from a ledge and adding mass to pull on the spring so we can measure the length to see how much the spring extends each time
When testing to see how much weight a spring can take before changing deformation what is meant by its natural length
It already starts to extend and so the natural weight would be from where it hasn’t been hung although it’s extremely small so we ignore it
What force would the spring have on the solid support holding it up
It will have an equal and opposite force upwards which is why it doesn’t fall when adding mass
The extension on a spring increases …
Proportionally
How can we write the force is proportional to e
F ∝ e
How much the extension increases proportionally depends on what
The spring constant
What is the symbol for the spring constant
k
What is the calculation that links force, spring constant and extension of a spring
F = k e
Force = spring constant x extension of a spring
What is the spring constant (k) measured in
N/m
What is extension measured in
Metres
What does the spring constant tell us
How many newtons it would take to stretch an object by 1m
True or False:
The higher the spring constant the stiffer the material
True
True or False:
The higher the spring constant the softer the material
False it would be stiffer
When spotting a force and extension graph what 3 things can we look for
- straight line
- goes through origin
- directly proportional
What is hooke’s law
Where a force and extension are directly proportional
What is the point where the straight line begins to curve on a force and extension graph called
Elastic limit which turns the deformation into an inelastic rather than elastic as it was before
