A 201-lb man decides to add to his exercise routine by walking up three flights of stairs (45 ft) 20 times per day. Hefigures that theworkrequired to increasehis potential energy in this way will permit him to eat an extra order of French fries, at 245 Cal, without adding to his weight. Is he correct in this assumption?

Key Concepts

Work and Energy

In physics, work is defined as the energy transferred when a force is applied over a distance. The work done against gravity to lift an object is calculated using the formula W = mgh, where W is work, m is mass, g is the acceleration due to gravity, and h is the height. Understanding this concept is crucial for determining the energy expenditure of the man as he walks up the stairs.

Potential Energy

Potential energy is the energy stored in an object due to its position in a gravitational field. For an object at height h, the potential energy can be expressed as PE = mgh. In this scenario, the man increases his potential energy by ascending the stairs, which can be quantified to assess whether he can offset the caloric intake from the French fries.

Caloric Energy and Conversion

Calories are a unit of energy commonly used to quantify the energy content of food and the energy expenditure of physical activities. One dietary Calorie (Cal) is equivalent to 1,000 calories (cal). To determine if the man can eat an extra order of French fries without gaining weight, it is essential to compare the energy expended from climbing the stairs to the caloric value of the fries.