A force of 4 kN is used to jack up the rear axle of a car by 25 mm. If this requires the operator of the jack to exert a force of 250 N through a distance of 0.6 m, what is (a) the velocity ratio, (b)...

A force of 4 kN is used to jack up the rear axle of a car by 25 mm. If this requires the operator of the jack to exert a force of 250 N through a distance of 0.6 m, what is (a) the velocity ratio, (b) the mechanical advantage and (c) the efficiency of the jack?

A simple machine has the law E = 0.3F + 0.2 kN and a VR of 7. Determine (a) the limiting MA, (b) the limiting efficiency, (c) the effort required to overcome friction when the load is zero.