# YAPQ: Non-homework physics question

#### Chaotic42

##### Lifer
Imagine a styrofoam bowl of 722mL capacity that has its bottom removed has been placed upside down in a microwave.

Further imagine that a hamburger with a mass of 500 grams has been placed on top of the inverted bowl.

Also imagine that the entire bowl/hamburger system started at STP and was then microwaved on high for two minutes.

At the sounding of the alarm, is the temperature inside the bowl less than, equal to, or greater than the temperature outside of the bowl?

#### Midlander

##### Platinum Member
Less than. But why would you do this?

Greater than?

#### Chaotic42

##### Lifer
Originally posted by: Midlander
Less than. But why would you do this?

The P stands for physics, not philosophy.

#### Midlander

##### Platinum Member
Originally posted by: Chaotic42
Originally posted by: Midlander
Less than. But why would you do this?

The P stands for physics, not philosophy.

:laugh:

#### iwantanewcomputer

##### Diamond Member
less, the water in the burger goes to vapor and greatly increases pressure which increases T

#### Atheus

##### Diamond Member
not a physicist, but i reckon temp depends on distance from focal center of the radiation, and how close to the frequency of the waves the resonant frequancy of the material is.

#### Atheus

##### Diamond Member
Originally posted by: iwantanewcomputer
less, the water in the burger goes to vapor and greatly increases pressure which increases T

Good point. The bowl would also insulate the small area inside it. Wouldn't most sten escape upward though?

#### Midlander

##### Platinum Member
Real answer: Microwaves heat fat faster than air. The hamburger gets hot and heats the air around it. The bowl (not really Styrofoam, but that's another topic) insulates the air under the bowl from the heat of the hamburger. Therefore, the air outside the bowl is hotter.

#### TuxDave

##### Lifer
Originally posted by: Midlander
Real answer: Microwaves heat fat faster than air. The hamburger gets hot and heats the air around it. The bowl (not really Styrofoam, but that's another topic) insulates the air under the bowl from the heat of the hamburger. Therefore, the air outside the bowl is hotter.

I thought that the bowl had the bottom removed so half the hamburger is exposed to a small insulated area and the other half is exposed to the rest of the microwave.

#### Chaotic42

##### Lifer
Edit: Make up your minds you crazy bastages!

#### TheShiz

##### Diamond Member
temperature inside the bowl is greater

#### Midlander

##### Platinum Member
Originally posted by: TuxDave
Originally posted by: Midlander
Real answer: Microwaves heat fat faster than air. The hamburger gets hot and heats the air around it. The bowl (not really Styrofoam, but that's another topic) insulates the air under the bowl from the heat of the hamburger. Therefore, the air outside the bowl is hotter.

I thought that the bowl had the bottom removed so half the hamburger is exposed to a small insulated area and the other half is exposed to the rest of the microwave.

Uh oh, I missed that. Then I change my answer. The volume of air under the hamburger is smaller than that around it, so it will heat faster.

#### iwantanewcomputer

##### Diamond Member
Originally posted by: Midlander
Real answer: Microwaves heat fat faster than air. The hamburger gets hot and heats the air around it. The bowl (not really Styrofoam, but that's another topic) insulates the air under the bowl from the heat of the hamburger. Therefore, the air outside the bowl is hotter.

this is also true. the microwaves have a very small heating effect on the air, they only heat the water/polar molecules in meat. the only way

Tinside the bowl is greater is if the microwave is really big, so the average air temp is still lower. this would also need the heat transfer through the bowl to be relatively high

edit: I also missed the bottom part. I change my answer