Home
Try this at home! PE and k
e) PE_{s} in terms of k - Ideal Spring
1. P.E._{s} = Fx
Average Force: F = F/2
2. PE = (F/2)x
F = Kx
3. P.E._{s} = (1/2)(Kx)x
Ex 1) A force of 12. N stretches a spring and makes it .15m longer a) What's the spring constant (k) of this spring?
k = F/x
= 12. N/.15 m
= 80. N/m
b) P.E. of this spring?
PE_{s} = (½)Kx^{2}
= 1/2(80. N/m)(.15 m^{2})
PE_{s} = .90 Joules
Ex 2) If 15. joules of energy are stored in the stretched spring, what is the value of the spring constant
15. J = (½)k(.50 m^{2})
15. J = .50 k(.25)
15 = .125 k
k = 120 N/m
©Tony Mangiacapre., - All Rights Reserved
[Home] |
|||||