Go Back   Physics Help Forum > High School and Pre-University Physics Help > Equilibrium and Elasticity

Equilibrium and Elasticity Equilibrium and Elasticity Physics Help Forum

Like Tree1Likes
  • 1 Post By ChipB
LinkBack Thread Tools Display Modes
Old Apr 22nd 2019, 03:09 PM   #1
Junior Member
Join Date: Apr 2019
Posts: 1
Arrow How far will the middle point of the beam sag under load?

There is a wooden beam with given size. We put 1kg in the middle point of beam. Question is how much will the middle point lower itself?

Young modulus is 1,18x10^10 Pa
Size of beam: length 1 meter , other two dimensions are 5cm and 0,5cm

The beam is supported on the ends of it.

We haven't learnt about this topic yet but I would like to have the answer. Is here anybody who would solve it for me please?
OlynthHA is offline   Reply With Quote
Old Apr 24th 2019, 04:43 AM   #2
Senior Member
Woody's Avatar
Join Date: Jun 2016
Location: England
Posts: 1,000
Not Ignoring You

I think you will find this is one of those "easy when you know how" problems.
However, unless you are actually working in a field that requires you regularly exercise this knowledge,
you are unlikely to know it "off the top of your head".

I had a quick poke around on the internet to see if I could find enough pointers to work out how to do it,
but then thought #insert expletive to taste# it,
you yourself say that you are expecting this to come up soon in your tuition.

Perhaps you can come back when your tutor has explained it to you, and explain it to us...

Last edited by Woody; Apr 24th 2019 at 04:47 AM.
Woody is offline   Reply With Quote
Old Apr 24th 2019, 07:28 AM   #3
Physics Team
ChipB's Avatar
Join Date: Jun 2010
Location: Morristown, NJ USA
Posts: 2,352
You can find formulas on line for beam equations, and a little searching would lead you to the formula for max deflection of a simply-supported beam with point load at the center:

$\delta = \frac {FL^3}{48 EI} $

You can determine the beam's moment of inertia, I, from the cross-section dimensions you provided. You will have to look up the value of Young's modulus, E, for the material the beam is made of.
Woody likes this.
ChipB is offline   Reply With Quote

  Physics Help Forum > High School and Pre-University Physics Help > Equilibrium and Elasticity

beam, load, middle, point, sag

Thread Tools
Display Modes

Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Load Measurements QuestionablePhysics Advanced Electricity and Magnetism 3 Apr 16th 2018 08:37 AM
shear stress at particular point in beam ling233 Advanced Thermodynamics 1 Nov 7th 2016 08:18 AM
Determine the load ling233 Kinematics and Dynamics 12 Nov 11th 2015 05:47 PM
Im trying to apply a force at the middle a column, how do i predict the maximum force yichenli Equilibrium and Elasticity 4 Sep 13th 2013 03:13 PM
Electric Field in Middle Square p75213 Electricity and Magnetism 1 Oct 2nd 2010 06:51 AM

Facebook Twitter Google+ RSS Feed