For an inclined plane, the mechanical advantage is calculated by,
M.A = (length of the incline)/(Height of the incline)
As the efficiency is 70%, we get
M.A = [tex] \frac{70}{100}*\frac{10}{3} [/tex]
=7/3
Force required to lift the load of 60 kg = Weight of the object/M.A
=[tex] \frac{60*9.8}{7/3} [/tex]
=252 N
To decrease the amount of effort, we can increase the length of the incline without changing its efficiency.
