ToughSTEM
Sign Up
Log In
ToughSTEM
A question answer community on a mission
to share Solutions for all STEM major Problems.
Cant find a problem on ToughSTEM?
0
A 10 m beam of mass 290 kg extends over a ledge. The beam is not attached, but simply rests on the surface. A 80 kg student intends to position the beam so that he can walk to the end of it. How far from the edge of the ledge can the beam extend?

Diagram of the Problem
Edit
Added Sat, 06 Jun '15
Community
1
Comment
Add a Comment
Solutions
0
First, draw a free body diagram.
Free Body Diagram for this Problem
Our givens :
        M = 290kg = Mass of Beam
        m = 80kg = mass of Student
        L = 10M = length of beam
        P = pivot point. 
        x = length of beam extended.

Then, set up our equilibrium equations.
      Tq =  Mg*(5-x) - mg * x + F*0 = 0
      >> Mg(5-x) = mg*x 
      
Now solve for X
      >> 5Mg - xMg = xmg
      >> 5Mg = x(M+m)
      >> 5M / (M + m) = x

Now plug in your Variables.
      5M / (M + m) = x
      5(290) / (290 + 80) = x
      3.918 = x = distance the beam can extend for a 80kg student to walk to the end.
   
When you actually do this problem, don't forget the units. 
I excluded them above because m for meters would be confusing with the previously defined variables.
 Carrying through your units is one of the most effective checking methods there is. 
Edit
Added Sat, 06 Jun '15
Community
1
Comment
Add a Comment
Add Your Solution!
Close

Click here to
Choose An Image
or
Get image from URL
GO
Close
Back
Add Image
Close
What URL would you like to link?
GO
α
β
γ
δ
ϵ
ε
η
ϑ
λ
μ
π
ρ
σ
τ
φ
ψ
ω
Γ
Δ
Θ
Λ
Π
Σ
Φ
Ω
Copied to Clipboard

Add Your Solution
Sign Up
to interact with the community. (That's part of how we ensure only good content gets on ToughSTEM)
OR
OR
ToughSTEM is completely free, and its staying that way. Students pay way too much already.
Almost done!
Please check your email to finish creating your account!
Welcome to the Club!
Choose a new Display Name
Only letters, numbers, spaces, dashes, and underscores, are allowed. Can not be blank.
Great! You're all set, .
A question answer community on a mission
to share Solutions for all STEM major Problems.
Why
The Purpose
How
The Community
Give Feedback
Tell us suggestions, ideas, and any bugs you find. Help make ToughSTEM even better.