Question

Задача по физике: Электрическая печь выделяет 100 кДж теплоты за 10 мин Определите величину тока и напряжения в печи, если сопротивление её нагревательного элемента 40 Ом

Answer 1

Q=I²Rt
I=√Q/Rt 
I=√100000/40*600=√4,17=2,04 A
U=IR=2,04*40=81,6 B

Answer 2

Task Analysis

To solve this problem, we can use the formula for electrical power, which is given by the equation:

P = V * I

Where: - P = power (in watts) - V = voltage (in volts) - I = current (in amperes)

We can rearrange this formula to solve for either voltage or current, and then use the given resistance to find the other quantity.

Calculating Power

First, let's calculate the power produced by the electric oven using the given information.

The power produced by the electric oven can be calculated using the formula:

P = E / t

Where: - P = power (in joules per second, or watts) - E = energy (in joules) - t = time (in seconds)

Given: - E = 100 kJ = 100,000 J - t = 10 minutes = 600 seconds

Substitute the given values into the formula to find the power produced by the electric oven.

P = 100,000 J / 600 s = 166.67 W

So, the power produced by the electric oven is 166.67 watts.

Calculating Current and Voltage

Next, we can use the power and resistance to find the current and voltage in the electric oven.

We can use the formula for power in terms of current and resistance:

P = I^2 * R

Where: - P = power (in watts) - I = current (in amperes) - R = resistance (in ohms)

Rearranging the formula to solve for current (I), we get:

I = sqrt(P / R)

Substitute the calculated power (P = 166.67 W) and the given resistance (R = 40 Ω) into the formula to find the current.

I = sqrt(166.67 W / 40 Ω) ≈ 2.58 A

So, the current in the electric oven is approximately 2.58 amperes.

Now, we can use the formula for power in terms of voltage and resistance:

P = V^2 / R

Rearranging the formula to solve for voltage (V), we get:

V = sqrt(P * R)

Substitute the calculated power (P = 166.67 W) and the given resistance (R = 40 Ω) into the formula to find the voltage.

V = sqrt(166.67 W * 40 Ω) ≈ 57.74 V

So, the voltage in the electric oven is approximately 57.74 volts.

Conclusion

Therefore, the current in the electric oven is approximately 2.58 amperes and the voltage is approximately 57.74 volts.