Finding spring constant and maximum acceleration

  • Thread starter chase222
  • Start date
  • #1
12
1
A 60 kg bungee jumper jumps from a bridge. She is tied to a 12 m long bungee cord and falls a total of 31 m. Calculate the spring constant of the bungee cord and the maximum acceleration experienced by the jumper.

I don't even know where to start. Can you tell me which equations I would use to find the answers to both parts of the problem?
 

Answers and Replies

  • #2
599
1
Find the formulas for the two forces involved, I suppose you can ignore friction wich leaves you with how many forces? Then use Newtons F=ma to find the resulting acceleration, and note that the first 12m are a free fall...
 
  • #3
cepheid
Staff Emeritus
Science Advisor
Gold Member
5,192
38
No, I won't tell you which equations to use. Instead, let's try to actually understand the problem: As always, start off with a free body diagram! What forces act on the jumper? It's easy...in this case there are only two. Gravity, and the restoring force of the bungee cord (it acts like a Hookian spring). So, what happens as she falls? Initially, the restoring force is zero. So gravity accelerates her downward. But the farther down she goes, the stronger the restoring force trying to pull her back up becomes. What happens at equilibrium? I.e. how can you determine what's going on at the point at which she stops falling? That's the key to solving this problem.
 

Related Threads on Finding spring constant and maximum acceleration

Replies
3
Views
11K
Replies
4
Views
7K
  • Last Post
Replies
3
Views
3K
Replies
1
Views
3K
Replies
4
Views
483
Replies
5
Views
96K
Replies
7
Views
6K
  • Last Post
3
Replies
67
Views
6K
Replies
2
Views
3K
Top