Question

60 баллов!!! ПОЖАЛУЙСТА ПОМОГИТЕ!!!Тело награли нагревателем мощностью 630 Вт сначала на capital delta t, а потом еще на capital delta t, но уже нагревателем с вдвое большей мощностью. В результате весь процесс нагревания занял время tau. Какая средняя мощность должна быть у нагревателя, чтобы сразу нагреть тело на 2 capital delta t за то же время tau? ответ выразить в Вт, округлить до целых. Потерями принебречь.

Answer 1

Q=c*m*dt. Если второй нагреватель в 2 раза мощнее, то для нагревания ему потребовалось в 2 раза меньше времени. Если первый нагрел тело за время t, то второй - за время t/2. Тогда тау=3*t/2 . Затраченная энергия равна Q*t+2*Q*t/2=2*Q*t=Q1*3*t/2, откуда Q1=4/3Q, а P=4*630/3=840 Вт

Answer 2

Calculation of Average Power

To find the average power required to heat the body, we need to consider two scenarios:

1. The body is initially heated by a heater with a power of 630 W for a time interval of Δt. 2. The body is further heated by a heater with double the power (1260 W) for an additional time interval of Δt.

Let's calculate the average power required in each scenario and compare them.

Scenario 1: Heating with a 630 W Heater for Δt

In this scenario, the body is initially heated by a heater with a power of 630 W for a time interval of Δt.

The energy supplied by the heater can be calculated using the formula:

Energy = Power × Time

The energy supplied by the 630 W heater is:

Energy1 = 630 W × Δt

Scenario 2: Heating with a 1260 W Heater for Δt

In this scenario, the body is further heated by a heater with double the power (1260 W) for an additional time interval of Δt.

The energy supplied by the 1260 W heater is:

Energy2 = 1260 W × Δt

Total Energy Supplied

The total energy supplied to the body is the sum of the energies supplied in both scenarios:

Total Energy = Energy1 + Energy2

Total Energy = 630 W × Δt + 1260 W × Δt

Average Power

The average power required to heat the body can be calculated using the formula:

Average Power = Total Energy / Total Time

Since the total time is 2Δt (the sum of the two time intervals), we can substitute the values:

Average Power = (630 W × Δt + 1260 W × Δt) / (2Δt)

Simplifying the expression:

Average Power = (630 W + 1260 W) / 2

Average Power = 945 W

Therefore, the average power required for the heater to heat the body by 2Δt in the same time interval τ is 945 W.

Please note that this calculation assumes no heat losses during the heating process, as mentioned in the question.

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