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
Correct Answer: Option C
Explanation
Efficiency = m.A x (frac{1}{V.R}) X 100%
75 = (frac{20 times 10}{effort}) x (frac{1}{frac{g}{sintheta}}) x 100%
Effort = 133.3N