Final answer:
You can play tennis for approximately 119 minutes on the energy in a candy bar. Exercise is necessary for weight loss but may not be sufficient.
Step-by-step explanation:
To determine how long you can play tennis on the energy in a candy bar, we need to calculate the energy expenditure of playing tennis.
On average, playing tennis burns about 6-8 calories per minute, depending on various factors such as intensity and body weight. Since 1 calorie is approximately equal to 4.18 joules, 200 kcal is equivalent to 836 kJ.
Assuming an average energy expenditure of 7 calories per minute, you could play tennis for approximately 836 kJ / 7 calories per minute = 119 minutes.
Now, in terms of whether 119 minutes seems like a long time, it depends on your individual perspective.
Some people may find it long, while others may find it not long enough.
It's important to remember that exercise alone may not be sufficient for weight loss.
To lose weight, you need to create a calorie deficit by balancing your energy intake from food with your energy expenditure through physical activity.