Definitions
What is the extension of a spring? (give a definition)
How much longer or shorter it is after force was applied to it
Limit of proportionality is the point where the applied stress causes an onset of permanent deformation.
False. Limit of proportionality is when the spring goes with Hooke's Law.
What is the formula for Hooke's law?
F=kx
What is a spring constant? (give a definition)
Some materials are stiffer than others. A spring constant controls how easily a material can be stretched
If you apply double the force to a spring, the displacement will be double as much. True or False?
True
What does the F, k and x stand for?
F= force k= spring constant x= change in length
What is restoring force?
The restoring force is a force that acts to bring a body to its equilibrium position.
If you inflate a balloon and then take the air out, you will observe that you have gone beyond the elastic limit of the balloon. True o False?
True
What is the spring constant of a car spring if a 2500 N force compresses it from a length of 5 m to a length of 3 m?
1250 N/m
If you apply twice as much force to a spring, will you expect its displacement to be twice as much or four times as much?
twice as much
Assume that you applied 2 N of force to a spring and the displacement was 10 m. If you apply 4 N of force, what will your displacement be?
20 m (force and displacement is proportional. If you double the force, your displacement will be doubled as well)
What is the elastic limit of a spring? (point E in the graph from yesterday)
How much you can stretch a spring before it deforms. (it's the maximum extension of a spring)
The stretchier a material is, the larger the spring constant is. True or False?
False. The stiffer a material is, the larger the spring constant is.
How much force is required to compress a 20m long spring to 15 m if the spring constant is 30 N/m?
150N
Imagine you have two springs A and B. If A is stiffer than B, will you expect A's spring constant to be larger or smaller than B's?
larger
What is Hooke's Law? (definition)
-The extension is proportional to the force -The spring will go back to its original length when the force is removed as long as we don’t exceed the elastic limit
If a spring goes beyond its elastic limit, we say that a spring is showing elastic behavior. True or False
False. the spring is showing plastic behavior
If John lays on a mattress with a force of 10N and the spring constant is 2 N/m, what is the displacement of the springs in the mattress?
5m
Why does Hooke's Law present the negative F= -kx?
The negative is talking about the restoring force. The sign just indicates you the direction of the force.