Question

1. Какую массу имеет медный проводник длиной 40 м, если напряжение на его концах равно 20 В, а сила тока, идущего по нему, равна 0,5 А? Удельное сопротивление меди равно 1,7*10-8 Ом*м, плотность – 8900 кг/м3.

Answer 1

по формуле R=U/I , R=p`l/S

а m=plS , отсюда S=уд.сопротивление * l * I/U

 

m=уд.сопр.*p *l2 I\U

Данные подставляем в формулу и считаем

 

Answer 2

R=U/I

R=p`l/S

m=plS

S=p`lI/U

m=p`pl2I\U, где p-плотность, а p`-уд. сопротивление

Подставляем данные из задачи в выражение.

У меня получилось 0,6*10-2 кг.

Answer 3

Calculation of the Mass of the Copper Conductor

To calculate the mass of the copper conductor, we can use the formula:

mass = volume x density

The volume of the copper conductor can be calculated using the formula:

volume = length x cross-sectional area

The cross-sectional area can be calculated using the formula:

cross-sectional area = (current x resistance) / voltage

Let's calculate the mass step by step.

1. Calculate the cross-sectional area: - Current (I) = 0.5 A - Resistance (R) = specific resistance x length / cross-sectional area - Specific resistance of copper (ρ) = 1.7 x 10^-8 Ω·m - Length (L) = 40 m - Voltage (V) = 20 V

Using the formula, we can calculate the cross-sectional area:

cross-sectional area = (0.5 A x (1.7 x 10^-8 Ω·m x 40 m)) / 20 V

Let's calculate the cross-sectional area using the given values:

cross-sectional area = (0.5 A x (1.7 x 10^-8 Ω·m x 40 m)) / 20 V = 0.000034 m^2

2. Calculate the volume: - Volume (V) = length x cross-sectional area

Using the given length and cross-sectional area, we can calculate the volume:

volume = 40 m x 0.000034 m^2 = 0.00136 m^3

3. Calculate the mass: - Density of copper (ρ) = 8900 kg/m^3

Using the given density and volume, we can calculate the mass:

mass = 8900 kg/m^3 x 0.00136 m^3 = 12.104 kg

Therefore, the mass of the copper conductor with a length of 40 m, a voltage of 20 V, and a current of 0.5 A is approximately 12.104 kg.

Please note that the calculations provided are based on the given information and assumptions.