Question 17.4: If the average meal consumed by an adult consists of about 4...

Modern Engineering Thermodynamics

If the average meal consumed by an adult consists of about 45.0% carbohydrate, 15.0% protein, and 40.0% fat, determine (a) the specific energy content of an average meal with natural state foods and (b) the total mass of an average meal needed to provide 10.5 MJ per day.

The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

a. The average energy content of natural (or wet) food components is

Carbohydrate:	$4.20 \text{MJ/kg}$
Protein:	$8.40 \text{MJ/kg}$
Fat:	$33.1 \text{MJ/kg}$

Therefore, the specific energy content of the average meal is

$e_\text{avg. meal} = 0.450 (4.20) + 0.150 (8.40) + 0.400 (33.1) = 16.4 \text{MJ/kg meal}$

b. A person who requires a daily food energy intake of $10.5 \text{MJ}$ must then consume

$\dot{m}_\text{avg. meal} = \frac{10.5}{16.4} = 0.640 \text{kg of average meal/day} = 1.4 \text{lbm of average meal/day}$

Related Answered Questions

Question: 17.10

The death rate constant for mice at 27.0°C is 0.0350 months^–1 . Determine the coefficient α in Eq. (17.33) for mice ...

Verified Answer:

At

T = 27.0°\text{C} = 300. \text{K}[/latex...

Question: 17.1

Using the concentration data provided in Table 17.2, determine the membrane potential in human cells of sodium, potassium, and chlorine ions at 37.0°C. ...

Verified Answer:

Table 17.2 gives the concentration of sodium ions ...

Question: 17.9

Determine the locomotion transport number of a 60.0 kg person traveling at 15.0 miles per hour on a 15.0 kg bicycle while expending 400. W of power pedaling. ...

Verified Answer:

Using Eq. (17.22) with

P = 400. \text{W},w ...

Question: 17.8

Determine the critical buckling height of a small tree whose base diameter is 5.00 × 10^–3 m ...

Verified Answer:

From Eq. (17.21), we have

h_\text{critical...

Question: 17.7

As a famous biomedical engineer, you are challenged on your medical exam to determine the heart rate and respiratory rate of a 0.0300 kg mouse, a 70.0 kg human, and a 4000. kg elephant. ...

Verified Answer:

The heartbeat rate for mammals in beats per minute...

Question: 17.6

Suppose you want to exercise off the energy added to your body as a result of eating one pint of ice cream by lifting weights. The external work done by the body equals the change in potential energy of the weights as they are lifted (there is no significant energy recovery within the body, however ...

Verified Answer:

Each lift requires that an amount of energy be put...

Question: 17.5

People living in affluent societies generally know very little about starvation. Most feel that death is imminent if food is withheld for only a week. However, we know that 1.00 kg of human body fat contains about 33.1 MJ of metabolizable energy, and it would be useful to know: a. The mass of body ...

Verified Answer:

a. A fasting person requiring

10.5 \text{M...

Question: 17.3

Determine the basal metabolic rate (BMR) per unit mass of an 80.0 kg adult human and an 8.00 gram mouse. Since both are warm-blooded mammals, explain why there is a difference in these values ...

Verified Answer:

The basal metabolic rate per unit mass of a warm-b...

Question: 17.2

Everyone has heard about the food chain, but few realize how inefficient it is in nature. The energy conversion efficiency from sunlight to plant growth is only about 1.00%, the energy conversion efficiency of the plants eaten by grazing herbivores is about 20.0%, and the energy conversion ...

Verified Answer:

Since our hunting carnivore requires

10.0 ...