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2 years ago

How many hours should I charge a 4.8 volt 600mah battery(it is urgent)

Engineering

1 answer:

miskamm [114]2 years ago

6 0

Answer:

For example, a 600maH pack should be charged at 600/10 or 60ma. This is known as the overnight rate. Although ideally, a pack should be fully charged in 10 hours, due to inefficiency, it will probably take between 12 and 15 hours.

Explanation:

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Which of the following is an example of an observation?

Novay_Z [31]

The monkey is brown!

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3 years ago

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vertical gate in an irrigation canal holds back 12.2 m of water. Find the average force on the gate if its width is 3.60 m. Repo

DanielleElmas [232]

Answer:

The right solution is "2625 kN".

Explanation:

According to the question,

The average pressure will be:

= $density\times g\times \frac{h}{2}$

By putting values, we get

= $1000\times 9.8\times \frac{12.2}{2}$

= $1000\times 9.8\times 6.1$

= $59780$

hence,

The average force will be:

= $Pressure\times Area$

= $59780\times 3.6\times 12.2$

= $2625537 \ N$

Or,

= $2625 \ kN$

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3 years ago

Please help i am give brainliest i really need help guys no links please ???

devlian [24]

Explanation:

The wind is an actual form of solar energy. winds are caused by the heating of the atmosphere by the sun, the rotation of the earth, and the earth's surface irregularities. The wind is capture in a wind turbine which provides a renewable energy source, the wind makes the rotor spin, as the rotor spins the movement of the blades drives a generator that creates energy, also known as wind power. The average wind efficiency of turbines is between 35-45%.

Advantages of wind power

- Wind power is cost-effective

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3 years ago

Air at 400kPa, 970 K enters a turbine operating at steady state and exits at 100 kPa, 670 K. Heat transfer from the turbine occu

Sonja [21]

Answer:

The rate of work developed is $\frac{\r W}{\r m}= 300kJ/kg$

The rate of entropy produced within the turbine is $\frac{\sigma}{\r m}= 0.0861kJ/kg \cdot K$

Explanation:

From the question we are told

The rate at which heat is transferred is $\frac{\r Q}{\r m } = - 30KJ/kg$

the negative sign because the heat is transferred from the turbine

The specific heat capacity of air is $c_p = 1.1KJ/kg \cdot K$

The inlet temperature is $T_1 = 970K$

The outlet temperature is $T_2 = 670K$

The pressure at the inlet of the turbine is $p_1 = 400 kPa$

The pressure at the exist of the turbine is $p_2 = 100kPa$

The temperature at outer surface is $T_s = 315K$

The individual gas constant of air R with a constant value $R = 0.287kJ/kg \cdot K$

The general equation for the turbine operating at steady state is \

$\r Q - \r W + \r m (h_1 - h_2) = 0$

h is the enthalpy of the turbine and it is mathematically represented as

$h = c_p T$

The above equation becomes

$\r Q - \r W + \r m c_p(T_1 - T_2) = 0$

$\frac{\r W}{\r m} = \frac{\r Q}{\r m} + c_p (T_1 -T_2)$

Where $\r Q$ is the heat transfer from the turbine

$\r W$ is the work output from the turbine

$\r m$ is the mass flow rate of air

$\frac{\r W}{\r m}$ is the rate of work developed

Substituting values

$\frac{\r W}{\r m} = (-30)+1.1(970-670)$

$\frac{\r W}{\r m}= 300kJ/kg$

The general balance equation for an entropy rate is represented mathematically as

$\frac{\r Q}{T_s} + \r m (s_1 -s_2) + \sigma = 0$

=> $\frac{\sigma}{\r m} = - \frac{\r Q}{\r m T_s} + (s_1 -s_2)$

generally $(s_1 -s_2) = \Delta s = c_p\ ln[\frac{T_2}{T_1} ] + R \ ln[\frac{v_2}{v_1} ]$

substituting for $(s_1 -s_2)$

$\frac{\sigma}{\r m} = \frac{-\r Q}{\r m} * \frac{1}{T_s} + c_p\ ln[\frac{T_2}{T_1} ] - R \ ln[\frac{p_2}{p_1} ]$

Where $\frac{\sigma}{\r m}$ is the rate of entropy produced within the turbine

substituting values

$\frac{\sigma}{\r m} = - (-30) * \frac{1}{315} + 1.1 * ln\frac{670}{970} - 0.287 * ln [\frac{100kPa}{400kPa} ]$

$\frac{\sigma}{\r m}= 0.0861kJ/kg \cdot K$

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4 years ago

In a team, a person’s efforts are less identifiable than when that person works independently. Because the person’s efforts are

Eduardwww [97]

The answer is deindividuation - a psychological state in which a person does not feel individual responsibility.

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3 years ago