Question

Larger animals use proportionately less energy than smaller animals; that is, it takes less energy per kg to power an elephant than to power a human. A 5000 kg African elephant requires about 70,000 Cal for basic needs for one day.
a. If a 68 human required the same energy per kg of body mass as an elephant, how much energy would be required each day?
b. What resting power does this correspond to?
C. How much less is this than the resting power noted in the chapter?

Answer 1

Answer:

Part a)

$Q = 952 cal/day$

Part b)

$P = 46 Watt$

Part c)

$\Delta P = 54 W$

Explanation:

As we know that 5000 kg African elephant requires 70,000 Cal for basic needs per day

so we will have

$m = 5000 kg$

$Q = 70,000 Cal$

so we have energy required per kg

$E = \frac{70,000}{5000}$

$E = 14 cal/kg$

Part a)

now we know that per kg the energy required will be same

so we have mass of the human is 68 kg

so energy required per day is given as

$Q = 68 \times 14$

$Q = 952 cal/day$

Part b)

Resting power is the rate of energy in Joule required per sec

so it is given as

$P = \frac{952 \times 4186}{24\times 3600}$

$P = 46 Watt$

Part c)

resting power given in the book is

$P' = 100 W$

so this is less than the power given

$\Delta P = 100 - 46$

$\Delta P = 54 W$