All categories

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.

You might be interested in

A hydraulic jump is induced in an 80 ft wide channel.The water depths on either side of the jump are 1 ft and 10 ft.Please calcu

krek1111 [17]

Answer:

a) 42.08 ft/sec

b) 3366.33 ft³/sec

c) 0.235

d) 18.225 ft

e) 3.80 ft

Explanation:

Given:

b = 80ft

y1 = 1 ft

y2 = 10ft

a) Let's take the formula:

$\frac{y2}{y1} = \frac{1}{5} * \sqrt{1 + 8f^2 - 1}$

$10*2 = \sqrt{1 + 8f^2 - 1$

1 + 8f² = (20+1)²

= 8f² = 440

f² = 55

f = 7.416

For velocity of the faster moving flow, we have :

$\frac{V_1}{\sqrt{g*y_1}} = 7.416$

$V_1 = 7.416 *\sqrt{32.2*1}$

V1 = 42.08 ft/sec

b) the flow rate will be calculated as

Q = VA

VA = V1 * b *y1

= 42.08 * 80 * 1

= 3366.66 ft³/sec

c) The Froude number of the sub-critical flow.

V2.A2 = 3366.66

Where A2 = 80ft * 10ft

Solving for V2, we have:

$V_2 = \frac{3666.66}{80*10}$

= 4.208 ft/sec

Froude number, F2 =

$\frac{V_2}{g*y_2} = \frac{4.208}{32.2*10}$

F2 = 0.235

d) $El = \frac{(y_2 - y_1)^3}{4*y_1*y_2}$

$El = \frac{(10-1)^3}{4*1*10}$

$= \frac{9^3}{40}$

= 18.225ft

e) for critical depth, we use :

$y_c = [\frac{(\frac{3366.66}{80})^2}{32.2}]^1^/^3$

= 3.80 ft

7 0

3 years ago

Read 2 more answers

A constant-head permeability test gives the following information: - Water flows horizontally through the soil sample. - The hei

Marysya12 [62]

Answer:

Complete answer to the question is explained in the attached files.please have a look on it.

Explanation:

5 0

3 years ago

90% of traffic crashes are due to driver error. True False

kumpel [21]

90% of traffic crashes are due to driver error.

True

3 0

2 years ago

Read 2 more answers

You want a potof water to boil at 105 celcius. How heavy a

ankoles [38]

Answer:

35.7 kg lid we put

Explanation:

given data

temperature = 105 celcius

diameter = 15 cm

Patm = 101 kPa

to find out

How heavy a lid should you put

solution

we know Psaturated from table for temperature is 105 celcius is

Psat = 120.8 kPa

area will be here

area = $\frac{\pi }{4} d^2$ ..................1

here d is diameter

put the value in equation 1

area = $\frac{\pi }{4} 0.15^2$

area = 0.01767 m²

so net force is

Fnet = ( Psat - Patm ) × area

Fnet = ( 120.8 - 101 ) × 0.01767

Fnet = 0.3498 KN = 350 N

we know

Fnet = mg

mass = $\frac{Fnet}{g}$

mass = $\frac{350}{9.8}$

mass = 35.7 kg

so 35.7 kg lid we put

3 0

3 years ago

21. Explique claramente como el fenotipo es el que favorece o desfavorece los resultados productivos obtenidos tanto en las expl

Montano1993 [528]

Los sistemas de producción pecuaria, son considerados como la estrategia social, económica y cultural más apropiada para mantener el bienestar de las comunidades, debido a que es la única actividad que puede simultáneamente proveer seguridad en el sustento diario, conservar ecosistemas, promover la conservación de la

6 0

3 years ago