- #1

I_Try_Math

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- Homework Statement
- A bungee cord is essentially a very long rubber band that can stretch up to four times its unstretched length. However, its spring constant varies over its stretch. Take the length of the cord to be along the x-direction and define the stretch x as the length of the cord l minus its un-stretched length l_0. Suppose a particular bungee cord has a spring constant, for 0 <= x <= 4.88, of k_1 = 204 N/m and for x > 4.88, of k_2 = 111 N/m (Recall that the spring constant is the slope of the force F(x) versus its stretch x.) (a) What is the tension in the cord when the stretch is 16.7 m (the maximum desired for a given jump)?

- Relevant Equations
- F(x) = kx

(a)

x = 16.7

Since x > 4.88, k = k_2 = 111 N/m.

T = F(16.7) = k_2*x = 111*16.7 = 1853.7 N

The answer key says the correct tension is 2320 N. Any help is appreciated, I'm not seeing where my math is wrong.

x = 16.7

Since x > 4.88, k = k_2 = 111 N/m.

T = F(16.7) = k_2*x = 111*16.7 = 1853.7 N

The answer key says the correct tension is 2320 N. Any help is appreciated, I'm not seeing where my math is wrong.