The last three photos are from HW1 to help answer Q3 on HW2 When you first put o

Question

The last three photos are from HW1 to help answer Q3 on HW2

When you first put out the solar cooker, it will start to heat up. As it becomes warmer than the surrounding environment, it will begin to lose energy to the environment. For the purposes of these calculations, assume that the air temperature is 300 K and the oven temperature is 310 K. 1. Estimate the rate of energy loss from your solar cooker due to conduction. Use the actual measurements from your oven in your calculation. 2. Estimate the rate of energy loss from your solar cooker due to radiation. Use the actual measurements from your oven in your calculation. (Note that the cup holding the water is what will do most of the radiating because that is where most of the energy is stored.) 3. Compare the power in from the sun (calculated on the last HW) to the power lost via conduction and radiation. What is the net rate that energy is absorbed (or lost) by the system? Under these conditions is your oven heating or cooling? 4. If so much energy is lost through the plastic wrap via conduction, why do we need it?

Explanation / Answer

You set your oven to 375 degrees Fahrenheit, just like your Grandma's perfect cookie recipe says. And 12 minutes later, they taste nothing like hers.

Don't blame yourself right away. Your oven might not be heating to the proper temperature.

Before you spend money on replacement parts or on a thermometer to hang inside your oven, try this simple experiment from the American Chemical Society's Reactions YouTube page to find out if that really is the problem.

All you need is some aluminum foil and table sugar.

Steps:

If your oven is at the right temperature, the first sugar sample should still be white, and the second should be golden brown and melty.

This is because the process of caramelization begins above 356 degrees Fahrenheit, and sugar begins melting at 367 degrees Fahrenheit.

So if both are white, your oven is running cool - it is heating to a lower temperature than what you're setting it to.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.