Answer:
it would take approximately 232 to 258 D cell batteries to power a human for 1 day.
Step-by-step 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.