# Determine the efficiency of the lever, with the help of which a load weighing 80 kg was raised

**Determine the efficiency of the lever, with the help of which a load weighing 80 kg was raised to a height of about 9 m. In this case, the larger arm of the lever, to which a force of 500 N was applied, was lengthened by 1.8 m.**

To find out the efficiency of the lever used, consider the formula: η = Apol / Azatr = mg * g * Δh / (F * l), where mg is the mass of the load (mg = 80 kg); g – acceleration of gravity (g ≈ 10 m / s2; const); Δh – movement (change in height) of the load (Δh = 0.9 m); F – force on the larger arm (F = 500 N); l – displacement of the larger arm (l = 1.8 m).

Let’s perform the calculation: η = mg * g * Δh / (F * l) = 80 * 10 * 0.9 / (500 * 1.8) = 0.8 or 80%.

Answer: The efficiency of the used lever, according to the calculation, is 80%.