Ladder Equilibrium: Solving for Forces at Hinged Point?

  • Thread starter Thread starter azwraith69
  • Start date Start date
  • Tags Tags
    Equilibrium
AI Thread Summary
The discussion revolves around solving for forces at the hinged point of a ladder in equilibrium. The user is attempting to apply the principles of net force and net torque to analyze the system but is struggling with the forces exerted by the hinge. A suggestion is made to choose a pivot point that avoids the need to consider hinge forces, which helps simplify the problem. The user acknowledges this advice and calculates the normal force as 150N. The conversation emphasizes the importance of strategic pivot selection in solving equilibrium problems.
azwraith69
Messages
7
Reaction score
0

Homework Statement


see the attachment below...

Homework Equations


net force = 0, net torque = 0
normal force(ground) = ?

The Attempt at a Solution


well, so far,,

net force(y) = normal force(floor) - weight(man) - weight(ladder) + ??(force exerted by hinge?)
net force(x) = 0 ( ?? )

Choosing the bottom of ladder as pivot point,
net torque = weight(ladder) x 2a + weight(man) x a - ??(force by hinge?)

First of all, sorry for not using latex..

The hinge is my problem, since I'm not familiar in solving with it.
What are the forces (and their directions) exerted on the ladder at the hinged point?
I really don't know..

And are my assignment of forces correct?

Thanks in advance..

I NEED THIS AFTER 10 HOURS...
So i have no time to reply, so please, I'm begging, please be direct to the point. And i hope each reply will help me..

Thank you guys..
 

Attachments

Physics news on Phys.org
Hint: Choose a pivot point that eliminates having to know anything about the forces at the hinge.
 
Doc Al said:
Hint: Choose a pivot point that eliminates having to know anything about the forces at the hinge.

thanks... i overlooked it since i always choose the point of contact with the ground as the pivot..

normal force = 150N ??

:)
 
You got it. :approve:
 
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 .
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...
Back
Top