9.5 Example 5

Calculate the support reactions, knowing that the beam has a mass of 4 kg and a length of 2.1 m.

Solution with FisicaLab

Select the group Static and, inside this, the module Static of solids. Erase the content of the chalkboard and select the SI system. And add one element Stationary reference system, one element Beam, six elements of beam and the necessary elements Force, as show the image below:

The Stationary reference system set the gravity value to default. Now to the element Beam, that we call Beam and assuming has its center of mass at middle, we have:

Name

Beam

m

4

lc

1.05

ang

0

Now to the elements of beam and its applied forces we have, from left to right:

Name

Beam

l

12 @ cm

f

30

To the element at 40 cm from the left side, we call RA the reaction:

Name

Beam

l

40 @ cm

f

RA

At 85 cm from the left side:

Name

Beam

l

85 @ cm

f

24

At 110 cm:

Name

Beam

l

110 @ cm

f

45

At 160 cm, we call RB the reaction:

Name

Beam

l

160 @ cm

f

RB

And at 195 cm, the last element:

Name

Beam

l

195 @ cm

f

33

Now click in the icon Solve to get the answer:

RB = 92.130 N ;  RA = 79.110 N ;
Status = success.