PHYS 101 Lecture Notes - Lecture 5: Bungee Cord
15 May 2018
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Phys 101 Written Problems #5
Due: Friday, Oct 20, 2017 at 4 PM. Put finished assignment in P101 drop box on 9000 level of Physics
(put into the box that has your tutorial section number as a label).
Please note to get full credit for any written homework assignment you must:
1) Put the assignment name, your full name, your student number, your tutorial section number
(see Canvas for tutorial sections), and TA first name (-1 mark if not done correctly) :
PHYS 101 – Homework #1, Susie Smith, 123456789, D102, Tim
2) Show all of your work, clearly and legibly. Use diagrams if necessary.
3) Try to work out answers symbolically. Only put #s in at the end.
4) Put a box around your answers.
5) Don’t forget units.
6) If you use more than one page, staple all of the pages together (-1 mark for unstapled
assignments)
a) You jump off a bridge with a (massless) bungee cord (a stretchable spring) tied around your
ankle. You fall for 15 m before the bungee cord begins to stretch. Your mass is 60 kg and we
assume the cord obeys Hooke’s law, F = –kx, with k = 55 N/m. If we neglect air resistance, use
conservation of energy to calculate the distance d below the bridge your foot will be before
coming to a stop. (3 marks)
b) What is the magnitude of the acceleration the cord exerts on you when it is fully extended? Give
answer in terms of multiples of g = 9.8 m/s2 (i.e. this is how many g’s it is exerting and we can
tolerate about 4-5 g’s before passing out). (1 mark)
