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3 years ago

How many D-cell batteries would it take to power a human for 1 day?

Engineering

1 answer:

lara31 [8.8K]3 years ago

6 0

Answer:

it would take approximately 232 to 258 D cell batteries to power a human for 1 day.

Explanation:

Estimate the recommended daily food intake (in Food Calories).

An average adult man requires between 2000 to 3000 calories per day.

Estimate the daily energy (in joule) a human needs.

As we know 1 food calorie is equal to 4.184 Joules of energy

2000*4.184 to 3000*4.184

8368 to 12552 Joules

But for engineering calculations 1 food calorie is equal to 1000 engineering calories, so

8368*1000 to 12552*1000

8368000 to 12552000 Joules

Estimate the voltage (in volt) of one D cell battery.

The voltage of a D cell battery is around 1.5 Volts

Estimate the charge (in amp-hours) of one D cell battery.

The amp-hours of a D cell battery varies with the manufacturing company, the typical amp-hours are in the range of 6 to 10 amp-hours.

Estimate the energy of one D cell battery (in watt-hour).

Energy in watt-hour is given by

voltage*amp-hour

1.5*6 to 1.5*10

9 to 15 watt-hour

Estimate the number of D-cell batteries it takes to power a human for 1 day.

First let us calculate the energy in a D cell battery,

1 watt-hour is equal to 3600 Joules

9*3600 to 15*3600

32400 to 54000 Joules

The number of D cell batteries required is found by dividing the energy need of a human by the energy stored in a D cell battery.

12552000/54000 to 8368000/32400

232 to 258 batteries

Therefore, it would take approximately 232 to 258 D cell batteries to power a human for 1 day.

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Answer:

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Explanation:

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k = 48.9 W/m - K

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$T_s = 285 degree celcius$

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Answer:

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Answer:

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velocity at exit = 29.34 m/sec

Explanation:

From the information given:

Inlet:

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Quality $x_1 = 0.2$

Outlet:

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