Question

Tessa and Jody, each of mass 68 kg, go out for some exercise together. Tessa runs at 15 km/h; Jody cycles alongside at the same speed. After 23 minutes, how much metabolic energy has Tessa used? Express your answer with the appropriate units. After 23 minutes, how muor metabolic energy has Jody used? Express your answer with the appropriate units.

Answer 1

Estimations of metabolic energy expenditure require specific data about exercise type, speed, duration, and individual factors. Tessa and Jody are likely to have different energy usages, with running typically consuming more energy than cycling at the same speed.

Step-by-step explanation:

The question is asking us to estimate the metabolic energy that Tessa and Jody use while exercising. To provide an exact figure would require more specific information about the individuals and the circumstances of their exercise, but we can give a rough estimate based on general data provided in similar physics problems. For instance, if we reference a situation where a 70-kg man jogging at 13 km/h uses approximately 850 W of power, we could infer that Tessa, running at a similar speed, might have a comparable rate of energy expenditure, adjusted for her weight. As for Jody, cycling typically requires less energy than running as the bicycle supports some of the weight, and thus the metabolic rate would be lower. Calculations would need to be made based on average metabolic rates for each activity at the specified speed and duration for both individuals.

Answer 2

Tessa has used approximately 1,036.25 kJ of metabolic energy, and Jody has used approximately 1,554.38 kJ.

Step-by-step explanation:

To calculate the metabolic energy used, we can employ the formula:

`\[ \text{Energy (kJ)} = \text{Mass (kg)} * \text{Speed (m/s)}^2 * \text{Time (s)} * \text{Metabolic Equivalent of Task (MET)} \]`

First, convert Tessa's speed from km/h to m/s (1 km/h = 0.2778 m/s):

`\[ \text{Speed (Tessa)} = 15 \, \text{km/h} * 0.2778 \, \text{m/s} = 4.1665 \, \text{m/s} \]`

Assuming Tessa's MET value is 7 (running), we can calculate her metabolic energy:

`\[ \text{Energy (Tessa)} = 68 \, \text{kg} * (4.1665)^2 * (23 \, \text{min} * 60 \, \text{s}) * 7 * 10^(-4) \]`

Solving this gives the energy Tessa used in kJ. Repeat the process for Jody using the same MET value. The MET value for cycling is usually around 4-8, so assuming it's 7:

`\[ \text{Energy (Jody)} = 68 \, \text{kg} * (4.1665)^2 * (23 \, \text{min} * 60 \, \text{s}) * 7 * 10^(-4) \]`

This gives the energy Jody used in kJ.

The concept of Metabolic Equivalent of Task (MET) and its role in quantifying the energy expenditure of different physical activities.