Alright, I'm stuck on a few problems with a physics brain teaser sheet. 1. Suppose you have a very small kitchen with a refrigerator. Can you cool off the kitchen by leaving the refreigerator door open? 2. Which bracing for a screen is strongest: two vertical bars, one horizontal bar crossing vertical bar, one diaganol bar, or a vertical bar. 3.A man is walking on a tight rope with the aid of a balance bar. Is a long or short bar better? Is a light or heavier bar better? Is a straight or bendy bar better? The last two I think I know, but the first one I'm not exactly sure. I know these seem dumb but can someone please respond.