A 20kg mass is to be pulled up a slope inclined at 30o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms-2]
A
13.3N
B
73.5N
C
133.3N
D
53.2N
Verified Correct Answer: C.
Physical Principles & Numerical Solution
Efficiency = m.A x \(\frac{1}{V.R}\) X 100%
75 = \(\frac{20 \times 10}{effort}\) x \(\frac{1}{\frac{g}{sin\theta}}\) x 100%
Effort = 133.3N
Source: Myschool Past Questions Archive (Record #28139)