• Support PF! Buy your school textbooks, materials and every day products Here!

Tension of strings in an elevator

  • Thread starter sodaMay
  • Start date
4
0
Two masses are connected by a string and are hanging from the ceiling of an elevator like this:

[string 1]
|
[4kg mass]
|
[string 2]
|
[6kg mass]

Show the tension of each string in the following situations:
i) Stationary
ii) Moving up at 3m/s
iii) Moving down at 3m/s
iv) Moving up at 3m/s/s
v) Moving down at 3m/s/s

Ok, I am kinda stumped. Where do I start? Is there a formula for tension? Is it F=ma? Or F=m(9.8-a) or something?

I'm just so horrible at physics, I'll be so grateful if someone could explain how this works..

Thanks! :)
 

Answers and Replies

35
0
You just need to look at the net force on each string. For example, you have two forces on the first string (weights of the hanging bodies). Other one is even easier. Remember the 1st Newton's law. That's when the elevator is stationary.

The formula [itex]F=ma[/itex] can be used in part (iv) and (v). It's the inertial force. Just be aware of its direction.
 

Related Threads for: Tension of strings in an elevator

Replies
10
Views
15K
Replies
3
Views
12K
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
7
Views
46K
  • Last Post
Replies
2
Views
6K
  • Last Post
Replies
2
Views
1K
  • Last Post
2
Replies
25
Views
2K
  • Last Post
Replies
6
Views
7K
Top