Question 3 of 3 · Frames, Machines & Pulleys · Foundation · About 12 min

Symmetric two-link lifting support

A $960\,\mathrm{N}$ vertical load is applied downward at pin $B=(0,1.6)\,\mathrm{m}$ . Two straight two-force struts connect $B$ to fixed pins at $A=(-1.2,0)$ and . Assume ideal pin joints and negligible member weight. Determine each strut force, specifying tension or compression, and the horizontal reaction magnitudes at the ground pins.

Two straight struts form an upside-down V. Top pin B at (0, 1.6) m. Ground pin supports at A (-1.2, 0) m and C (1.2, 0) m. A downward force arrow above B. Dimensions of 1.20 m and 1.20 m under the base, 1.60 m on a vertical line on the far right, and 2.0 m beside each strut. Labels: A; B; C; 960 N; 1.20 m; 1.20 m; 1.60 m; 2.0 m; 2.0 m — Schematic, not to scale unless dimensions are given.

Given

Two struts 2.0 m long
$1.2$ m horizontal run, $1.6$ m rise
Vertical load 960 N at top

Find

Strut $AB$ force
Strut $BC$ force
Horizontal support reaction magnitude

Assumptions

All members and connections are idealised as specified in the question.
Use g = 9.81 m/s^2 where gravitational acceleration is required.

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Symmetric two-link lifting support

Given

Find

Assumptions

Worked solution