FM1 - Hookes Law Flashcards
What does Hookes law say?
Extension is proportional to force
What is an unstretched metal wire called?
Natural length
If a metal is supported at the top and then a weight is attached at the bottom was happens?
It stretches - the weight pulls down with force F, is producing an equal and opposite force at the support
- Also happens in helical springs
What did Robert Hooke discover in 1676?
That the extension of a stretched wire is propotional to the load or force
How will a metal spring also obey Hookes Law?
If a pair of opposite forces are applied to each end
How can you investigate Hookes Law?
Use a spring
What equipment do you need to investigate Hookes Law?
- A clamp
- Spring
- A hanging mass
- Weighted stand
- Extra masses
Describe a method for measuring Hookes Law?
1) Measure length of spring without any load (natural length)
2) Add one mass at a time allowing the spring to come to a rest, then measure new length of spring -record results
3) The extension is the change in length from the original length
4) Repeat this process and calculate an average
When does Hookes Law stop working?
When the force is great enough
What should Hookes look like for a metal wire on a graph?
A straight line relationship between force and extension
What happens on a graph when the force becomes great enough?
The graph starts to curve - it is called the elastic limit
If a metal is supported at the top and then a weight is attached at the bottom was happens?
It stretches - the weight pulls down with force F, is producing an equal and opposite force at the support
- Also happens in helical springs
What did Robert Hooke discover in 1676?
That the extension of a stretched wire is propotional to the load or force
How will a metal spring also obey Hookes Law?
If a pair of opposite forces are applied to each end
How can you investigate Hookes Law?
Use a spring
