A load weighing 1200 H is lifted to a height of 0.12 m. At this, a force of 360 N is applied to the long arm.

A load weighing 1200 H is lifted to a height of 0.12 m. At this, a force of 360 N is applied to the long arm. Determine the efficiency of the lever if, when the load is lifted, the point of application of the force has dropped by 0.5 m of the immovable.

P = 1200 N.

h = 0.12 m.

F = 360 N.

S = 0.5 m.

Efficiency -?

Efficiency coefficient Efficiency shows what part of the spent work Az, expressed as a percentage, goes into useful work Ap: Efficiency = Ap * 100% / Az.

Useful work when lifting a body with the lever An is expressed by the formula: An = m * g * h, where m is the mass of the load, g is the acceleration of gravity, h is the height of the inclined plane.

The weight P of the lifted load is expressed by the formula: P = m * g.

Ap = P * h.

The expended work Az is expressed by the formula: Az = F * S.

The formula for determining the efficiency of the lever will take the form: efficiency = P * h * 100% / F * S.

Efficiency = 1200 N * 0.12 m * 100% / 360 N * 0.5 m = 80%.

Answer: the lever has an efficiency of 80%.