Equations 2 Flashcards
A spring has a spring constant,(k), Of 3N/m. It is stretched until it is extended by 50 cm. Calculate the elastic potential energy stored by the spring, assuming it is not stretched beyond the limit of proportionality.
Ee= 1/2 x k x e²
Ee=0.5 x 3 x 0.5²
Ee=0.4J
define elastic potential energy store
When we stretch an object such as a spring, we give it a store of elastic potential energy. We can calculate it using the equation:
Ee= 1/2 k e²
If the extension of a trampoline spring is 0.3m, and it’s spring constant is 1.8 N/m, how much work has been done on the spring?
Ee= 1/2 x k x e²
Ee=0.5 x 1.8 x 0.3²
Ee=0.081J
What trend does the Graphs show? And at what point is the spring stretch beyond the limit of proportionality?
For a given spring and other elastic objects the extension is directly proportional to the force applied. For example, if the force is doubled, the extension doubles. The point at which the spring stretched beyond the limit of proportionality is where the line bends upward
Describe the spring constant and extension of a spring.
The extension of a spring is the extra length it has been stretched-not the total length. The spring constant tells us how stiff the spring is: A high k means you have to use a lot of energy to stretch the spring
A spring in a church Clock has a spring constant of 12N/m. How much work must be done on the spring in order to stretch it 4.8m?
Ee= 1/2 x k x e² Ee= 0.5 x 12 x 4.8² Ee= 138.2J
HT A spring in a car’s suspension has elastic potential energy store 36J. If the spring constant is 8 N/m, find the extension.
Ee=1/2 x k x e²
e2 = E/ 1/2 x k
e2 = 36/ (0.5 x 8)
e2 =9 e = 3m
HT A giant spring has spring 400 N/m and elastic potential energy store 96kJ. Calculate it’s extension.
Ee = 1/2 x k x e² e2 = E/ 1/2 x k e2 = 96 / (0.5 x 400) e2 = 0.48 e = 0.7m
