Friction Coefficients and Minimum Normal Force

AI Thread Summary
The discussion revolves around calculating the minimum normal force required for a climber supported by friction in a vertical chimney. The climber's weight is 68 kg, with static coefficients of friction of 0.78 for shoes against the wall and 0.55 for the back against the wall. The user initially struggled with understanding the forces acting on the climber and the net force involved. After some deliberation and drawing free body diagrams, the user successfully figured out the solution. The conversation highlights the importance of analyzing forces and friction in physics problems.
Sligh
Messages
10
Reaction score
0

Homework Statement



The 68 kg climber in Fig. 4-52 is supported in the "chimney" by the friction forces exerted on his shoes and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.78 and 0.55, respectively. What is the minimum normal force he must exert? Assume the walls are vertical and that friction forces are both at a maximum.

2. The attempt at a solution

I have drawn some free body diagrams, but I cannot quite grasp this question. Any help towards a solution would be greatly appreciated.
 
Physics news on Phys.org
Well, what forces act on the climber? What's the net force?
 
Thanks anyhow. I figured it out now. ;)
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Normal force at the base of a ladder
Replies
20
Views
2K
Coefficient of kinetic friction of a block sliding across the ceiling
Replies
7
Views
1K
Is friction really always related to the normal force?
Replies
5
Views
2K
Direction of the normal force when acting on a tilted object
Replies
9
Views
3K
Find the frictional force between a block and a wall
Replies
5
Views
3K
Coefficient of friction of a sandwiched body
Replies
15
Views
858
Calculating Forces on a Motorcycle Riding in a Transparent Sphere
Replies
5
Views
2K
Calculating Minimum Normal Force for a Climber in a Vertical Chimney
Replies
10
Views
4K
Friction - problem with one of the equilibrium equations
Replies
13
Views
2K
Coefficient of Friction when Normal Force is Reduced [HS]
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top