Question

10. Ящик с гвоздями, масса которого 54 кг, поднимают на 5 этаж строящегося дома при помощи подвижного блока, действуя на трос силой 360 Н. Вычислите КПД установки.

Answer 1

Дано                                  Решение:           Вычисления:m =54 кг                                  η = Ап /Aз *100%                            P = 54кг * 9,8 Н /кг » 540 Н                   h1 = Х м                                    Ап = P* h 1                                             η= 540 / 2*360 * 100% = 75%                                                                   h2=  2*X м                                         Aз  =F * h2        F = 360H                                      Р = m* g           g = 9,8 H/кг                        η=P*  h 1 / F * h2 *100%=                                              P*X / F* 2X* 100%=                                                                                                  P/ 2 F* 100%η -?                                                                  Ответ : η=75%   вроде так

Answer 2

Calculation of Efficiency (КПД) of the System

To calculate the efficiency (КПД) of the system, we need to determine the work input and the work output.

The work input is given by the force applied to the rope multiplied by the distance over which the force is applied. In this case, the force applied to the rope is 360 N, and the distance is the height of the 5 floors. Assuming each floor is approximately 3 meters high, the total distance is 5 floors * 3 meters/floor = 15 meters.

Therefore, the work input is:

Work input = Force * Distance = 360 N * 15 m = 5400 Nm

The work output is given by the weight of the box multiplied by the distance it is lifted. The weight of the box is given as 54 kg, and the distance it is lifted is the same as the height of the 5 floors, which is 15 meters.

Therefore, the work output is:

Work output = Weight * Distance = 54 kg * 9.8 m/s^2 * 15 m = 7938 Nm

Now, we can calculate the efficiency (КПД) of the system using the formula:

Efficiency (КПД) = (Work output / Work input) * 100%

Substituting the values we calculated:

Efficiency (КПД) = (7938 Nm / 5400 Nm) * 100% = 146.78%

Please note that the calculated efficiency is greater than 100%. This could be due to various factors such as measurement errors, frictional losses, or other inefficiencies in the system.