Question

Какова сила тока в обмотке электродвигателя подъемного крана, когда он за 30 с равномерно поднимает груз массой 2 т на 10 м? Напряжение в сети 380 В, КПД двигателя 75 % С дано и решением

Answer 1

Ответ: 23,4А

Объяснение:

Дано:

t=30c

m=2т=2000кг

h=10м

g=10Н/кг

U=380В

η=75%=0,75

---------------

I-?

mgh/t=UIη

I=mgh/(Utη)=2000*10*10/(380*30*0,75)=23,4А

Answer 2

Calculation of Current in the Motor Winding

To calculate the current in the motor winding of the lifting crane, we can use the formula:

Current (I) = Power (P) / (Voltage (V) * Efficiency (η))

Given: - Voltage in the network (V) = 380 V - Efficiency of the motor (η) = 75% - Time taken to lift the load (t) = 30 s - Mass of the load (m) = 2 t - Height lifted (h) = 10 m

First, let's calculate the power (P) required to lift the load:

Power (P) = Work done (W) / Time (t)

The work done to lift the load can be calculated using the formula:

Work done (W) = Force (F) * Distance (d)

The force required to lift the load can be calculated using the formula:

Force (F) = Mass (m) * Acceleration due to gravity (g)

The acceleration due to gravity (g) is approximately 9.8 m/s^2.

Substituting the values into the formulas:

Force (F) = 2 t * 9.8 m/s^2 = 19.6 kN

Work done (W) = 19.6 kN * 10 m = 196 kNm

Power (P) = 196 kNm / 30 s = 6.53 kW

Now, let's calculate the current (I) using the formula mentioned earlier:

Current (I) = 6.53 kW / (380 V * 0.75) = 22.9 A

Therefore, the current in the motor winding of the lifting crane when it uniformly lifts a 2-ton load for 30 seconds over a height of 10 meters is approximately 22.9 Amperes.

Please note that the calculations provided are based on the given information and assumptions.