Question

1.   A 400.0-N sign hangs from the end of a uniform strut. The strut is 4.0 m long and weighs 600.0 N. The strut is supported by a hinge at the wall and by a cable whose other end is tied to the wall at a point 3.0 m above the left end of the strut. Find the tension in the supporting cable and the force of the hinge on the strut.

Answer 1

Solution:

The tension in the supporting cable

$\sum\tau_B=0\to600\cdot2+400\cdot4-4T\cdot(3/5)=0\to T=1167\ (N)$ . Answer

The force of the hinge on the strut.

$F_h=T\cdot(4/5)=1167\cdot(4/5)=933\ (N)$

$\sum\tau_A =0\to600\cdot2-F_v\cdot4=0\to F_v=300\ (N)$

$F=\sqrt{933^+300^2}=980\ (N)$. Answer