Question

Тепловой двигатель с КПД 20% получил от нагревателя 4.2× 10^6 Дж теплоты. Определить полезную работу , совершенную данным тепловым двигателем

Answer 1

КПД=(A(пол)/Q)*100%
A(пол)=0,2*4200000=840000Дж=840 кДж

Answer 2

Calculation of Useful Work by the Thermal Engine

To determine the useful work performed by the thermal engine, we need to know the efficiency (η) of the engine and the amount of heat (Q) supplied to it.

Given: - Efficiency (η) of the thermal engine: 20% or 0.2 - Heat supplied (Q) to the engine: 4.2 × 10^6 J

To calculate the useful work (W) performed by the thermal engine, we can use the formula:

W = η × Q

Substituting the given values into the formula, we get:

W = 0.2 × 4.2 × 10^6 J

Now, let's calculate the value of W:

W = 0.2 × 4.2 × 10^6 J = 0.84 × 10^6 J = 8.4 × 10^5 J

Therefore, the useful work performed by the thermal engine is 8.4 × 10^5 J.

Please note that the calculation assumes that the efficiency remains constant throughout the operation of the thermal engine.