1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Maximum load force

  1. Jan 3, 2017 #1
    1. The problem statement, all variables and given/known data
    A uniform pine beam, 3.6 m long and 9.5 cm x 14 cm in cross section, rests on two supports near its ends, as shown. The beam’s mass is 25 kg and two vertical roof supports rest on it, each one-third of the way from the ends. What maximum load force FL can each of the roof supports exert without shearing the pine beam at its supports? Use a safety factor of 5.0.
    2. Relevant equations

    3. The attempt at a solution

    Answer sheet:
    F= 1/5 x A x Maximum stress

    I just don't understand the first step. Why did I multiply it by 1/5??? And what does safety factor mean?
  2. jcsd
  3. Jan 3, 2017 #2
    Safety factor is how many times stronger the member is than it needs to be.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted