The velocity ratio of a machine is 5 and its efficiency is 75%. What effort would be needed to lift a load of 150N with the machine?
-
A.
20N -
B.
30N -
C.
40N -
D.
50N
Correct Answer: Option C
Explanation
Efficiency = M.A/V.R
75% = M.A/V.R
75/100 = M.A/5
M.A = 75(5)/100 = 3.75
But M.A = Load/Effort
3.75 = 150/Effort
Effort = 150/3.75
Effort = 40N