Question

Электрокипятильник со спиралью сопротивлением 160 Ом помещен в сосуд ,содержащий 0,5 кг воды при 20 градусах цельсия , и включили его в сеть с напряжением 220 В.Через 5 мин спираль выключили .Какова температура воды в сосуде?Потерями теплоты пренебречь. нужно срочнооо

Answer 1

Электрокипятильник выделил кол-ство теплоты, которое мы рассчитаем по формуле Q=J²Rt. J найдем по закону Ома для участка цепи  J=U/R=220/160=1,375А. Т.о. Q=90750 Дж (минуты перевести в секунды). Удельная теплоемкость воды - 4200.
Найдем Δt по формуле Δt=Q/cm. Δt=43. Тогда конечная температура равна 20+43=63 градуса.

Answer 2

Calculation of the final temperature of the water in the vessel

To calculate the final temperature of the water in the vessel after the electric kettle with a resistance coil of 160 Ohms is turned off, we can use the formula for heat transfer:

Q = m * c * ΔT

Where: - Q is the heat transferred to the water (in Joules) - m is the mass of the water (in kilograms) - c is the specific heat capacity of water (approximately 4186 J/kg°C) - ΔT is the change in temperature of the water (in °C)

Given: - m = 0.5 kg (mass of water) - c = 4186 J/kg°C (specific heat capacity of water) - ΔT = ? (change in temperature of the water)

We need to find ΔT, the change in temperature of the water.

To find Q, the heat transferred to the water, we can use the formula:

Q = V * I * t

Where: - V is the voltage (in volts) - I is the current (in amperes) - t is the time (in seconds)

Given: - V = 220 V (voltage) - I = V / R (current, where R is the resistance) - R = 160 Ω (resistance) - t = 5 min = 300 s (time)

Substituting the given values, we can calculate I:

I = V / R = 220 V / 160 Ω = 1.375 A

Now, we can calculate Q:

Q = V * I * t = 220 V * 1.375 A * 300 s = 90,750 J

Now, we can substitute the calculated value of Q into the first equation to find ΔT:

90,750 J = 0.5 kg * 4186 J/kg°C * ΔT

Simplifying the equation:

ΔT = 90,750 J / (0.5 kg * 4186 J/kg°C) ≈ 43.3°C

Therefore, the change in temperature of the water is approximately 43.3°C.

To find the final temperature of the water, we add the change in temperature to the initial temperature of 20°C:

Final temperature = Initial temperature + ΔT = 20°C + 43.3°C ≈ 63.3°C

Therefore, the final temperature of the water in the vessel is approximately 63.3°C.

Please note that this calculation assumes no heat loss to the surroundings, as stated in the question.