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39 votes
A 60-kg person consumes a small order of french fries (250.0 Cal) and wishes to “work off” the energy by climbing a 11 m stairway. How many vertical climbs are needed to use all the energy?

User Racheli
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3.3k points

2 Answers

21 votes
21 votes

Final answer:

A 60-kg person would need to climb an 11 m stairway approximately 162 times to expend the energy from a 250.0 Cal serving of french fries.

Step-by-step explanation:

To determine how many vertical climbs a 60-kg person would need to do to use all the energy from a 250.0 Cal (Calorie with a capital 'C' is equivalent to a kilocalorie in scientific terms) portion of french fries, we can use the concept of work done against gravity, which in physics is equivalent to potential energy (PE = mgh, where m is mass in kilograms, g is the acceleration due to gravity, and h is the height in meters).

First, we convert calories to joules because the standard unit for energy in Physics is the joule (J). Since 1 dietary Calorie is equal to 4184 joules, 250.0 Calories are equal to 1,046,000 joules.

Next, we calculate the work needed for one climb. For a 60 kg person climbing 11 meters, the work done (W) is given by: W = mgh = (60 kg)(9.8 m/s^2)(11 m) = 6468 joules per climb.

To find out how many climbs are needed to expend 1,046,000 joules, we divide the total energy to be expended by the energy used per climb: Number of climbs = 1,046,000 joules / 6468 joules per climb, which equals approximately 162 climbs.

User Michael Haephrati
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3.2k points
25 votes
25 votes

Answer:

1.78 KM

Step-by-step explanation:

Well he need to use work that provide him that potential energy.

P.E = mgh

250 cal * (4184 J)/(1 cal) = 1,046,000 J
So 250 cal consists of (1,046,000 J)
They might equals each other right? (Conservation of energy)
1,046,000 = mgh (divide mg to both)

h = (1,046,00)/(mg)

h = (1,046,000)/(60*9.8)= 1778.9 = 1.7789 KM

User Rudger
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3.2k points