Module 3 - Springs Flashcards
Describe the criteria for an object to be compressed or stretched
- Two forces
- Equal in magnitude
- Opposite in direction
Why does the magnitude of the two forces that cause deformation need to be equal in magnitude
If they are not equal in magnitude then there will be a resultant force which will cause the object to accelerate rather than deform
What are the two main forces linked to strings and what type of deformation do they cause
- Tensile Forces: Cause extension due to tension
- Compressive Forces: Cause compression
What is meant by deformation
The change in shape due to tensile or compressive forces
What is meant by extension
- The change in length due to deformation
State Hooke’s Law
For a material up to its limit of proportionality, the force applied is directly proportional to the extension of the material
When will an object not follow Hooke’s law
When the material has been extended passed its limit of proportionality
What is the equation linked to Hooke’s law
F (Force) = k (Force constant) x X(Extension)
What is meant by the Force Constant
- It is a measure of the stiffness of the spring (N/m)
What is the relationship with the difficulty to stretch a spring and the springs Force Constant
- The greater the force constant of a spring for the same extension, a greater force is needed
How do you calculate the force constant of a spring
- Draw and F/x graph
- Find the gradient of the graph within its elastic region
What is meant by Elastic Deformation
- When an object is extended within its elastic limit so changes shape but returns to its original length once the force is removed
What is meant by Plastic Deformation
- When an object is extended passed its elastic limit so changes shape but does not returns to its original length once the force is removed
