Suppose that with a pulley system, you need to exert a force of 1,400 N to lift a heavy object. But without the pulley system, you need to exert 4,200 N to lift the object. What is the mechanical advantage of the pulley system

3

Explanation:

Mechanical Advantage: This can be defined as the ratio of the load to the effort of a machine. Mechanical advantage has no unit because it is a ratio of two quantity of the same unit.

It can be expressed as

M.A = L/E Equation 1

M.A = Mechanical advantage, L = Load, E = Effort.

Given: L = 4200 N, E = 1400 N

Substitute into equation 1

M.A = 4200/1400

M.A = 3

Hence the mechanical advantage of the pulley system = 3

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards