In a screw jack, the effort required to lift the load is given by (where W = Load lifted, ≈í¬± = Helix angle, and ≈ì√ú = Angle of friction.)$

P = W tan (≈ì√ú - ≈í¬±)

P = W tan (≈í¬± - ≈ì√ú)

P = W tan (≈í¬± + ≈ì√ú)

P = W cos (≈í¬± + ≈ì√ú)

In a screw jack, the effort required to lift the load is given by (whe

1.	In a screw jack, the effort required to lift the load is given by (where W = Load lifted, ≈í¬± = Helix angle, and ≈ì√ú = Angle of friction.)$
A.	P = W tan (≈í¬± - ≈ì√ú)
B.	P = W tan (≈í¬± + ≈ì√ú)
C.	P = W tan (≈ì√ú - ≈í¬±)
D.	P = W cos (≈í¬± + ≈ì√ú)
Answer» C. P = W tan (≈ì√ú - ≈í¬±)