CP13 Flashcards
Can an object be stretched, bent or compressed using only one force?
No, an object requires more than one force to stretch, bend or compress.
What does it mean when an object is elastic?
When an object is elastic, it means that it will return to its original shape when the forces are removed.
What does it mean when an object is inelastic?
When an object is inelastic, it means that it will keep the new shape (that was created from the forces) after the forces are removed.
Can objects go from being elastic to inelastic, and if so, what objects can?
Yes, some objects are elastic when the forces are small but behave inelastically if the forces are too big. Metals can be made into springs that behave elastically, but if the forces used to stretch them are too big they become permanently deformed.
What is the extension (of a spring)?
The extension of a spring (or other object) is the change in length when forces are applied.
How does a force-extension graph tell us if an object is elastic or inelastic?
If the line is directly proportional for force and extension, then the object is elastic as that shows us that it can return to its original shape, however if the line is no longer directly proportional, then the object is inelastic as the proportionality has changed and the object has changed shape.
How can you use springs and weights to work out the extension of a spring?
You will need to measure the length of the spring before adding any weight (force) onto it and after adding the weight (force) onto it and subtract them from each other. The result is the extension of the spring.
What is spring constant?
A measure of how stiff a spring is. The spring constant is the force needed to stretch a spring by 1m.
What is the equation for force (that involves spring constant and extension)?
Force(N) = Spring constant(N/m) x Extension(m)
What is the symbol equation for force (that involves spring constant and extension)?
F = k x X (F=Force, k=Spring constant, X= Extension)
What is work done?
A measure of the energy transferred when a force acts through a distance.
What is the formula triangle for force (that involves spring constant and extension)?
Force
Spring constant | Extension
What is the formula for energy transferred in stretching (that involves spring constant and extension)?
Energy transferred in stretching(J) = 1/2 x Spring constant(N/m) x Extension² (m²)
What is the symbol equation for energy transferred in stretching (that involves spring constant and extension)?
E = 1/2 x k x X² (E=Energy transferred in stretching, k=Spring constant, X=Extension)
What is the formula triangle for energy transferred in stretching (that involves spring constant and extension)?
Energy
1/2 | Spring constant | (Extension)²
