An "energy bar" contains 18 g of carbohydrates. If the energy bar was his only fuel, how far...

Question:

An "energy bar" contains 18 g of carbohydrates. If the energy bar was his only fuel, how far could a 68 kg person walk at 5 km/h?

Calories Inside the Energy Bar:

Calories gained by eating the energy bar is different from the calories gained by the energy. The difference lies in the first alphabet. The lower case calorie denotes 1 calorie is gained and the upper case Calorie denotes 1000 calories.

According to the data:

{eq}1\ \textrm{carb} =4\frac{\textrm{Cal}}{g} {/eq}

Answer and Explanation:

Given:

Amount of carbohydrates in the energy bar is {eq}18\ g {/eq}

Mass of the person is {eq}m=68\ kg {/eq}

Speed of the person is {eq}v=5\ km/h {/eq}

For the energy content in the energy bar:

{eq}E_t=18\times 4\\ E_t=72\ \textrm{Calories} {/eq}

For the conversion of calories into joules:

{eq}1\ \textrm{Cal}=4184\ J\\ 72\ \textrm{Cal}=4184\times 72\\ 72\ \textrm{Cal}=301248\ J {/eq}

Now for the kinetic energy of the person:

{eq}K.E=\frac{1}{2}mv^2\\ K.E=\frac{1}{2}68\times (1.38)^2\\ K.E=64.7\ J {/eq}

Now for the distance traveled by the person:

{eq}S=\frac{E_t}{K.E}\\ S=\frac{301248}{64.7}\\ S=4656\ m\\ S=4.656\ km {/eq}

Thus, the distance traveled by the person is 4.656 km


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What is Energy Conservation? - Definition, Process & Examples

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