A plane inclined at an angle of 30o to the horizontal has an efficiency of 60%. The force parallel to the plane required to push a load of 120N uniformly up the plane is
A
60N
B
100N
C
120N
D
200N
E
240N
Verified Correct Answer: B.
Physical Principles & Numerical Solution
V.R = \(\frac{1}{sin 30}\) = 2
Efficiency = \(\frac{m.A}{V.R}\) x 100%
60 = \(\frac{120}{effort}\) x \(\frac{1}{2}\) x 100
Effort = 100N
Source: Myschool Past Questions Archive (Record #28700)