The electric motor of the crane is connected to a 220 V current source, while the current in the winding is 5 A.

| January 29, 2021 | education

The electric motor of the crane is connected to a 220 V current source, while the current in the winding is 5 A. Determine the efficiency of the crane if it lifts a load weighing 1 ton to a height of 15 m in 1 minute.

To find the value of the efficiency of the specified crane, we apply the formula: η = Apol / Azatr = m * g * Δh / (U * I * t).

Reference data: q – acceleration due to gravity (q ≈ 9.8 m / s2).

Data: m is the mass of the cargo (m = 10 ^ 3 kg); Δh – movement of the load, change in height (Δh = 15 m); U is the voltage of the current source (U = 220 V); I is the current in the winding (I = 50 A, inaccuracy in the condition); t – elapsed time (t = 60 s).

Calculation: η = m * g * Δh / (U * I * t) = 10 ^ 3 * 9.8 * 15 / (220 * 50 * 60) ≈ 0.223 or 22.3%.

Answer: The specified crane should have an efficiency of 22.3%.



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