Question

one food calorie is equal to 4184 j. when you workout to burn off calories your system is only 25 % efficient and 75% of the energy used is converted to heat. the good news is that you only have to perform 1000 j of work to burn off one calorie. suppose that you drink a small can of pepsi that has a food value of 150 calories, and you want to burn off the calories by lifting a sack of 100 small apples, which has a total weight of 100 newtons, one meter. how many times would you have to lift the sack one meter to accomplish this?

Answer 1

To burn off the calories from the small can of Pepsi by lifting a sack of 100 small apples, you would have to lift the sack one meter 25,104 times.

Step-by-step explanation:

To burn off the calories from the small can of Pepsi, we need to perform 150 calories x 4184 J/cal = 627,600 J of work. However, our body is only 25% efficient, so we need to perform 627,600 J / 0.25 = 2,510,400 J of total energy.

Lifting the sack of 100 small apples requires lifting a total weight of 100 N x 1 m = 100 J of work every time. So, to accomplish 2,510,400 J of total energy, we need to lift the sack 2,510,400 J / 100 J = 25,104 times.

Answer 2

To calculate the number of times you would have to lift the sack to burn off the calories from the small can of Pepsi, we need to determine the energy required to burn off one calorie by performing 1000 J of work. Then, we can calculate the number of times you would have to lift the sack by dividing the energy required to burn off the calories by the work done lifting the sack.

Step-by-step explanation:

To calculate the number of times you would have to lift the sack to burn off the calories, we need to first determine the energy required to burn off one calorie. According to the information provided, you need to perform 1000 J of work to burn off one calorie. Since each food calorie is equal to 4184 J, you would need to perform 4184 imes 1000 J of work to burn off 4184 J. Now, we can calculate the number of times you would have to lift the sack one meter:

1. Calculate the energy required to burn off 150 calories: 150 imes 4184 imes 1000 J
2. Calculate the total work done lifting the sack one meter: 100 imes 1 N imes 1 m
3. Divide the energy required to burn off the calories by the work done lifting the sack: (150 imes 4184 imes 1000 J) / (100 imes 1 N imes 1 m)

The result will give you the number of times you would have to lift the sack one meter to burn off the calories from the small can of Pepsi.