Question

В резисторе сопротивлением 360 Ом при напряжении 15 В электрическим током была совершена работа 450 Дж. За какое время была совершена работа? (подробное решение)

Answer 1

Надеюсь поможет тебе))

Answer 2

A=U^(2)t /R;t=AR/U^(2)=450*360 /15*15=720 (c)=12 (минут).

Answer 3

Problem Analysis

We are given the resistance of a resistor (360 Ω), the voltage across it (15 V), and the work done (450 J). We need to find the time taken to do this work.

Formula for Work Done

The work done (W) in an electrical circuit can be calculated using the formula:

W = V * Q

where: - W is the work done (in joules) - V is the voltage (in volts) - Q is the charge (in coulombs)

Relationship between Charge and Time

The relationship between charge (Q) and time (t) can be expressed as:

Q = I * t

where: - Q is the charge (in coulombs) - I is the current (in amperes) - t is the time (in seconds)

Relationship between Voltage, Current, and Resistance

The relationship between voltage (V), current (I), and resistance (R) can be expressed as:

V = I * R

where: - V is the voltage (in volts) - I is the current (in amperes) - R is the resistance (in ohms)

Solution

To find the time taken to do the work, we need to determine the charge (Q) and the current (I).

1. First, let's find the charge (Q) using the formula for work done:

W = V * Q

Substituting the given values: 450 J = 15 V * Q

Solving for Q: Q = 450 J / 15 V Q = 30 C

2. Next, let's find the current (I) using the relationship between voltage, current, and resistance:

V = I * R

Substituting the given values: 15 V = I * 360 Ω

Solving for I: I = 15 V / 360 Ω I ≈ 0.0417 A

3. Finally, let's find the time (t) using the relationship between charge and time:

Q = I * t

Substituting the known values: 30 C = 0.0417 A * t

Solving for t: t = 30 C / 0.0417 A t ≈ 719.28 s

Answer

The work of 450 J was done in approximately 719.28 seconds.