A body of mass 7.5 kg is to be pulled up along a plane which is inclined at 30o to the horizontal. If the efficiency of the plane is 75%, what is the minimum force required to pull the body up the plane?

(g = 10ms-1)

A. 5.0 N

B. 20.0 N

C. 50.0 N

D. 75.0 N

E. 200.0 N

AriyomiNewbie

V.R= 1/ sin¢

V.R=>1/sin 30

= 1/1/2

= 2

Efficiency = MA/ VR × 100%

75%= MA/ 2×100

75/100=MA/2

MA= 1.5

Note that weight= Load= Mg

= 7.5×10

=75

MA= Load/Effort

1.5= 75/ E

E= 75\1.5

E= 50N