How to solve this problem ?

Attachment 15529

Please answer in steps

Thank you

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- Feb 21st 2010, 12:04 PMmj.alawamiPhysics -equilibrium
How to solve this problem ?

Attachment 15529

Please answer in steps

Thank you - Feb 21st 2010, 12:28 PMGrandad
Hello mj.alawamiThe beam is $\displaystyle 8$ m in length; it is uniform. So its weight acts $\displaystyle 4$ m from each end.

If the reaction forces at A and B are $\displaystyle R_A$ and $\displaystyle R_B$ kg-wt respectively, take moments about A:

$\displaystyle 450 \times 4 + 220\times 5.6 -8R_B=0$Solve this equation for $\displaystyle R_B$.

Then resolve vertically (or take moments about B) to find $\displaystyle R_A$.

Can you complete it now?

Grandad - Feb 21st 2010, 12:41 PMmj.alawami
- Feb 21st 2010, 04:43 PMskeeter
- Feb 21st 2010, 10:12 PMGrandad
- Feb 21st 2010, 10:40 PMmj.alawami
- Feb 22nd 2010, 01:52 AMGrandad
Hello mj.alawamiNo. Let me re-phrase my first post, take the sum of the vertical forces and equate to zero:

$\displaystyle 450g+220g -R_A - R_B = 0$(Some people denote this by $\displaystyle \sum F_y=0$.)

Substitute the value we've found for $\displaystyle R_B$ and solve for $\displaystyle R_A$.

Grandad