AP Physics B

posted by .

A 63.6-kg bungee jumper is standing on a tall platform (h0 = 50.6 m). The bungee cord has an unstrained length of L0 = 9.54 m and, when stretched, behaves like an ideal spring with a spring constant of k = 67.8 N/m. The jumper falls from rest, and it is assumed that the only forces acting on him are his weight and, for the latter part of the descent, the elastic force of the bungee cord. Determine how far the bungee jumper is from the water when he reaches the lowest point in his fall.

  • AP Physics B -

    potential energy lost in fall = potential energy gained by our perfect cord

    m g (fall distance) = (1/2) k (stretch distance)^2

    63.6(9.81)(fall) = (1/2)(67.8)(fall-9.54)^2

    623.9 f = 33.9 (f-9.54)^2

    18.4 f = f^2 - 19.1 f + 91.0

    f^2 - 19.1 f + 72.6 = 0

    f = [ 19.1 +/- sqrt (365 - 290) ]/2

    f = (19.1 +/- sqrt 75 )/2

    f = (19.1 +/- 8.7) /2
    = 13.9 or 5.2
    5.2 is no good, shorter than cord unstretched
    so
    f = 13.9
    50.6 - 13.9 = 36.7 above water

    check my arithmetic !!!

  • AP Physics B -

    Thank You So Much!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A bungee jumper, whose mass is 87 kg, jumps from a tall platform. After reaching his lowest point, he continues to oscillate up and down, reaching the low point two more times in 8.5 s. Ignoring air resistance and assuming that the …
  2. Physics - bungee jumping

    In a head dip bungee jump from abridge over a river, the bungee cord is fastened to the jumpers ankles. The jumper then steps off and falls towards the river until the cord becomes taut. At that point, the cord begins to slow the jumper's …
  3. Physics

    A bungee jumper, whose mass is 83 kg, jumps from a tall platform. After reaching his lowest point, he continues to oscillate up and down, reaching the low point two more times in 9.7 s. Ignoring air resistance and assuming that the …
  4. Physics

    A 63.0-kg bungee jumper is standing on a tall platform (h0 = 45.8 m). The bungee cord has an unstrained length of L0 = 9.18 m and, when stretched, behaves like an ideal spring with a spring constant of k = 67.2 N/m. The jumper falls …
  5. Physics

    A 63.0-kg bungee jumper is standing on a tall platform (h0 = 45.8 m). The bungee cord has an unstrained length of L0 = 9.18 m and, when stretched, behaves like an ideal spring with a spring constant of k = 67.2 N/m. The jumper falls …
  6. physic

    Bungee Jumping. A bungee jumper jumps from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from hitting the water! …
  7. Physics Classical Mechanics

    A bungee jumper jumps (with no initial speed) from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from hitting …
  8. science

    A bungee jumper jumps (with no initial speed) from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from hitting …
  9. physics

    A 61.0 -kg bungee jumper is standing on a tall platform (h0 = 46.0 m), as indicated in the figure. The bungee cord has an unstrained length of L0 = 9.00 m, and when stretched, behaves like an ideal spring with a spring constant of …
  10. physics

    A 61.0 -kg bungee jumper is standing on a tall platform (h0 = 46.0 m), as indicated in the figure. The bungee cord has an unstrained length of L0 = 9.00 m, and when stretched, behaves like an ideal spring with a spring constant of …

More Similar Questions