Question

Плиту массой 600 кг поднимают за 10 мин на 20 м. Определите совершенную работу и мощность подъёмного крана . если его КПД 80%

Answer 1

По формуле КПД=Ап / Аз. ( Ап -полезная работа (по подъему груза) , Аз - затраченная работа ( крана) )
Ап=m*g*h . ( m -масса=600кг, g -ускорение свободного падения=10м/c^2, h -высота =20м )
Аз=N*t . ( N -мощность крана, t -время=600с КПД=0,8 ). подставим
КПД=m*g*h / N*t . выразим мощность.
N=m*g*h / КПД*t .
N=600*10*20 / 0,8*600=250 Вт. ты ничего не напутала в условиях, уж очень маленькая мощность ???Проверь.
Вычислим работу
Аз=N*t .
Аз=250*600=150000 Дж

Answer 2

Calculation of Work and Power

To determine the work done and the power of the lifting crane, we need to use the formula:

Work (W) = Force (F) x Distance (d)

The force can be calculated using the formula:

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

where the acceleration due to gravity is approximately 9.8 m/s².

Given: - Mass of the stove (m) = 600 kg - Distance lifted (d) = 20 m - Time taken (t) = 10 min = 600 s

First, let's calculate the force:

Force (F) = 600 kg x 9.8 m/s²

Now, let's calculate the work done:

Work (W) = Force (F) x Distance (d)

Finally, we can calculate the power using the formula:

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

However, we also need to take into account the efficiency (η) of the lifting crane, which is given as 80%. The efficiency is defined as the ratio of useful output energy to the input energy.

Power (P) = (Work (W) / Time (t)) / Efficiency (η)

Let's calculate the values:

Calculation Steps:

1. Calculate the force: - Force (F) = 600 kg x 9.8 m/s² = 5880 N.

2. Calculate the work done: - Work (W) = Force (F) x Distance (d) = 5880 N x 20 m = 117,600 J.

3. Calculate the power: - Power (P) = (Work (W) / Time (t)) / Efficiency (η) = (117,600 J / 600 s) / 0.8 = 196 W.

Therefore, the work done by the lifting crane is 117,600 J, and the power of the lifting crane is 196 W, assuming an efficiency of 80%.

Please note that the calculations assume a constant force and neglect any other factors that may affect the actual work and power output of the lifting crane.