Question

R=5 Ом U=4.5 В А=729 Дж t=?

Answer 1

Ответ:

180 секунд

Объяснение:

P = A/t

Закон Джоуля-Ленца:

 P = UI = U^2/R

Отсюда P = 4,5^2/5 = 4,05 Вт

а вот отсюда t = A/ P = 180 секунд

Answer 2

To find the value of time (t), we can use the formula:

Energy (E) = Power (P) × time (t)

Power (P) can be calculated using the formula:

Power (P) = Voltage (U) × Current (I)

Given: Resistance (R) = 5 Ω Voltage (U) = 4.5 V Energy (E) = 729 J

First, let's calculate the current (I) using Ohm's Law:

Voltage (U) = Current (I) × Resistance (R)

Rearranging the formula, we have:

Current (I) = Voltage (U) / Resistance (R)

Substituting the given values, we get:

I = 4.5 V / 5 Ω I = 0.9 A

Now, let's calculate the power (P):

P = U × I P = 4.5 V × 0.9 A P = 4.05 W

Finally, we can find the time (t):

E = P × t

Rearranging the formula to solve for t:

t = E / P

Substituting the given values, we get:

t = 729 J / 4.05 W t ≈ 180 seconds

Therefore, the value of time (t) is approximately 180 seconds.