Friction and inclines problem. i need help

  • Thread starter Terrell
  • Start date
  • #1
317
26
[moderator note: moved from technical forums, no template]

this is fun but i am stuck. help! :) the first image states the problem and the second image is my futile attempt at a solution
 

Attachments

  • aggh problem.png
    aggh problem.png
    12 KB · Views: 399
  • agghhh.png
    agghhh.png
    15.2 KB · Views: 371
Last edited by a moderator:

Answers and Replies

  • #2
PeroK
Science Advisor
Homework Helper
Insights Author
Gold Member
2021 Award
21,952
13,279
You need a better free body diagram, showing the forces at the top and bottom of the ladder.
 
  • #3
wrobel
Science Advisor
Insights Author
997
856
Theorem. If a rigid body is in rest then the sum of torques about any point is equal zero and the sum of forces is also equal zero.
It is convenient to calculate torques about one of two contact points of the ladder and the wall/floor.
 
  • #5
317
26
Theorem. If a rigid body is in rest then the sum of torques about any point is equal zero and the sum of forces is also equal zero.
It is convenient to calculate torques about one of two contact points of the ladder and the wall/floor.
can i solve this without torques? i haven't got into torques just yet
 
  • #6
haruspex
Science Advisor
Homework Helper
Insights Author
Gold Member
38,184
7,800
can i solve this without torques? i haven't got into torques just yet
No. You have three unknowns, the two normal forces and the angle. So you need three equations. Only two are available from linear force balances in two dimensions, so your third must be from torque balance.
 

Related Threads on Friction and inclines problem. i need help

Replies
5
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
5
Views
5K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
10
Views
2K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
1
Views
1K
Top