What is the correct answer?


In a screw jack, the effort required to lift the load is given by (where W = Load lifted, α = Helix angle, and φ = Angle of friction.)

A. P = W tan (α - φ)

B. P = W tan (α + φ)

C. P = W tan (φ - α)

D. P = W cos (α + φ)

Correct Answer :

B. P = W tan (α + φ)

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