A plane inclined at an angle at 30o to the horizontal has an efficiency of 50%. The force parallel to the plane required to push a load of 120 N uniformly up the plane is
A
40√3N
B
60N
C
120N
D
200N
E
240N
Verified Correct Answer: C.
Physical Principles & Numerical Solution
E = \(\frac{\text{M.A}}{\text{V.R}}\) ; \(\frac{50}{100}\) = \(\frac{\text{M.A}}{2}\)
M.A = 1; \(\frac{\text{L}}{\text{E}}\) = 1
E = L = 120N
Source: Myschool Past Questions Archive (Record #24084)