Joules, Food Calories, & Kilojoules - Unit Conversion With Heat Energy - Physics Problems

TL;DR

Learn how to convert units of heat energy, such as joules and calories, with step-by-step examples.

Transcript

this video is all about units of heat energy we're going to talk about how to convert from one unit to another so let's work on this problem convert 500 joules into calories now you need to know the conversion factor one calorie is 4.184 joules so given that information how can we convert joules into calories so start with what you're given in that... Read More

Key Insights

• 🧑‍🏭 The conversion factor for converting joules to calories is 1 calorie = 4.184 joules.
• 😋 To convert kilojoules to food calories, perform multiple conversions: kilojoules to joules, joules to calories, and calories to food calories.
• 😋 The conversion factor between grams of fat and food calories is 1 gram of fat = 9 food calories.
• 😋 Food calories can be converted to joules by multiplying by 1000 and then by 4.184.

Questions & Answers

Q: How do you convert 500 joules to calories?

To convert joules to calories, use the conversion factor of 1 calorie = 4.184 joules. Divide 500 joules by 4.184 to get the answer of 119.5 calories.

Q: How do you convert 750 kilojoules to food calories?

Convert kilojoules to joules (1 kilojoule = 1000 joules), then joules to calories (1 calorie = 4.184 joules), and calories to food calories (1 food calorie = 1000 calories). Divide 750 kilojoules by 4.184 to get the answer of 179.3 food calories.

Q: How many joules of chemical energy are stored in a cheeseburger with 700 food calories?

To convert food calories to joules, multiply 700 food calories by 1000 calories (1 food calorie = 1000 calories), then multiply by 4.184 joules (1 calorie = 4.184 joules). The answer is 2,928,800 joules.

Q: What is the joules of chemical energy stored in 15 grams of fat?

Convert grams of fat to food calories using the conversion factor of 1 gram of fat = 9 food calories. Then, convert food calories to calories (1 food calorie = 1000 calories) and calories to joules (1 calorie = 4.184 joules). Multiply 15 grams by 9, then by 1000, then by 4.184 to get the answer of 564,840 joules.

Summary & Key Takeaways

• Convert 500 joules to calories using the conversion factor of 1 calorie = 4.184 joules.

• Convert 750 kilojoules to food calories by converting kilojoules to joules, joules to calories, and calories to food calories.

• Determine the joules of chemical energy stored in a cheeseburger with 700 food calories.

• Calculate the joules of chemical energy stored in 15 grams of fat using the conversion factor of 1 gram of fat = 9 food calories.