The 25-kg flowerpot is supported at A by three cords. Determine the force acting in each cord for equilibrium.

1 Answer | Add Yours

shumbm's profile pic

Borys Shumyatskiy | College Teacher | (Level 3) Associate Educator

Posted on

Hello!

The forces are acting along the ropes.

Denote their magnitudes as B, C and D in accordance with the points of attachment.

For reasons of symmetry C=D. It is sufficient to get two independent equations.

Project forces on the y-axis:

`B*sin(45°) = 2*C*cos(30°)*sin(60°),`

or `B = C*sqrt(2)*(3/2),`

and on the z-axis:

`2*C*cos(30°)*cos(60°) + B*cos(45°) = mg,`

or `C*sqrt(3)/2 + B*1/sqrt(2) = mg.`

Substitute from the first equation into the second:

`C*(sqrt(3)/2 + 3/2) = mg,` or

`C*2.37 approx 25*9.8=245,` or

`C approx 245/2.37 approx 103.4 (N).`

So `B approx 103.4*2.12 approx 219.2 (N).`

The answer: B=219.2 N, C=D=103.4 N.

We’ve answered 318,912 questions. We can answer yours, too.

Ask a question