How many kilocalories does a runner expend when he runs for 4.5 h and uses 710 Cal/h? How many pieces of pizza that each contain 12 g of protein, 11 g of fat, and 30 g of carbohydrates could be eaten after the race to replenish these calories?

To calculate the total number of kilocalories the runner expended, we can multiply the hours of running by the calories expended per hour:

Total calories expended = 4.5 h * 710 Cal/h

Total calories expended = 3195 Cal

Since 1 kilocalorie is equal to 1 Calorie, the runner expended 3195 kilocalories.

Now, let's calculate how many pieces of pizza would be needed to replenish these calories.

Each piece of pizza contains 12 g of protein, 11 g of fat, and 30 g of carbohydrates. To calculate the total calories in one piece of pizza, we can use the following conversion factors:

1g of protein = 4 calories
1g of fat = 9 calories
1g of carbohydrates = 4 calories

Total calories in one piece of pizza = (12 g * 4 calories/g) + (11 g * 9 calories/g) + (30 g * 4 calories/g)

Total calories in one piece of pizza = 48 calories + 99 calories + 120 calories

Total calories in one piece of pizza = 267 calories

To find the number of pieces of pizza that would replenish the runner's calories, we divide the total calories expended by the calories in one piece of pizza:

Number of pieces of pizza = 3195 calories / 267 calories

Number of pieces of pizza ≈ 12 pieces

Therefore, approximately 12 pieces of pizza would be needed to replenish the calories expended by the runner.

To find out how many kilocalories a runner expends when running for 4.5 hours at a rate of 710 Cal/h, we can multiply the number of hours by the calories expended per hour.

Calories expended = Time (hours) x Calories per hour

Calories expended = 4.5 h x 710 Cal/h

Calories expended = 3195 kilocalories (kcal)

Now, let's calculate how many pieces of pizza would provide the same amount of kilocalories (3195 kcal). To do this, we need to know the nutritional content of a piece of pizza.

Let's assume that one piece of pizza contains 12 grams of protein, 11 grams of fat, and 30 grams of carbohydrates.

First, we need to calculate the total calories provided by protein, fat, and carbohydrates in one piece of pizza.

Calories from protein = 12 grams x 4 kcal/gram = 48 kcal
Calories from fat = 11 grams x 9 kcal/gram = 99 kcal
Calories from carbohydrates = 30 grams x 4 kcal/gram = 120 kcal

Total calories per piece of pizza = 48 kcal (protein) + 99 kcal (fat) + 120 kcal (carbohydrates) = 267 kcal

To find out how many pieces of pizza would replenish the expended calories (3195 kcal), we can divide the total expended calories by the calories per piece of pizza.

Number of pieces of pizza = Expended calories / Calories per piece of pizza

Number of pieces of pizza = 3195 kcal / 267 kcal

Number of pieces of pizza ≈ 11.98

Since we can't have a fraction of a piece of pizza, the runner could eat around 12 pieces of pizza to replenish the expended calories after the race.