Forces And Elasticity Flashcards
How can an object shape change?
Stretching - forces is opposite directions away from object
Bending - forces that distort object
Compressing - forces in opposite directions towards object
Example of forces involve in compressing
Placing a mass on top of a spring placed on flat surface. The forces are : weight of mass, reaction force from surface to spring.
Example of forces involve stretching
Placing a mass on the bottom of a vertically hanging spring. Two forces are - weight of mass and the tension of spring. Away from each other.
Examples of forces on bending
Diving board bending when a swimmer stands at far end.
Two forces - weight of swimmer, reaction force - block to diving board. Act toward each other but at different points of the object.
What is elastic deformation?
When object returns to its og shape when the stretching force is removed
What is inelastic deformation
When objects remain stretched and don’t return completely to og shape even when the stretching force is removed.
What is hookes law?
The extension of an elastic object is directly proportional to the force applied, up to the limit of proportionality’s
Hookes law equation
Force = spring contact x extension
F =ke
What can the symbol of e represent
Extension or compression
What happens when a force stretches or compresses a spring?
It does work and EPE is stored in the spring. If the spring is not inelastically deformed, work done on spring and EPE stored are qual.
Linear vs non linear relationship between force and extension
Materials that obey hookes law - straight line on force, extension graph - linear.
Don’t obey - f and e are not dp then they have non linear relationship. - curve.
Calculating spring constant
K = f/e - shows that k is equal to force per unit extension needed to extend the spring. Stiffer spring - greater spring constant
