Physics
Study the diagram and answer the questions that follow.
(a) In the diagram, is the worker attempting to raise or lower the load?
(b) Justify your answer to (a) with the necessary calculation.
Force
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Answer
(a) Worker is attempting to lower the load.
(b) For rotational equilibrium about the fulcrum,
Clockwise Moment = Anticlockwise Moment
Assuming 1 kgf ≈ 9.8 N, we convert W1 = 4000 kgf ≈ 4000 x 9.8 = 39,200 N
- Moment due to Load (anticlockwise) :
M1 = W1 d1 = 39,200 x 25 = 980,000 Nm - Moment due to Worker’s Force (clockwise) :
M2 = F2 x d2 = 20,000 x 10 = 200,000 Nm
The clockwise moment (200,000 Nm) is much less than the anticlockwise moment (980,000 Nm). Their applied force is insufficient to raise the load, so that worker will lower the load.
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