A student of mass m drops off a tower of height h, tethered to the bungee cord. The elasticity of the bungee cord is hosen so that its effective spring constant is k = 2mg/h. The jump is begun a zero speed at altitude h with the bungee cord fastened vertically above her, barely taut(with no slack), but under no initial tension.(adsbygoogle = window.adsbygoogle || []).push({});

(a) Choose a convenient coordinate systerm to analyze the problem.

- | h k = 2mg/h kx = F(x). I'm not sure what they are

- | want here because to me we

- | put it all in terms of x

- | as it's the only direction

- | considered.

- |

- O

(b) What is the initial total mechanical energy of the student?

I used the Energy for a simple harmonic oscillator and get..

E = 1/2(k)(x)^2

E = (mgx^2)/2

(c) SHow that the student will arrive at the ground with zero kinetic energy.

... I'm not sure about this one

(d) At what height above the ground is the speed of the student a maximum. I think it's at the point when it changes direction and oscillates back

(e) Will the same bungee cord be safe to use for a jump from the same tower(of height h) for a person with mass m' < m? With mass m' > m? Explain your reasoning.

No for both. The force of the spring doesn't depend on the mass, but only on the displacement and spring constant of the spring.

Is the work correct, not exactly, or absolutely wrong =\

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# Homework Help: Work, Energy, and the CWE Theorem

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