Two identical bowls of casserole need to bekept warm. The cook covers bowl 1 with transparent plastic wrapand bowl 2 with shiny aluminum foil, in each case trapping a layerof air between the covering and the casserole. (a) After a few minutes, will the temperature of casserole 1 be greater than, less than,or equal to the temperature of casserole 2? (b) Choose the bestexplanation from among the following:I. The lower thermal conductivity of the plastic wrap over casserole 1 will suppress heat loss by conduction better than aluminum foil.II. In each case heat loss by convection is suppressed, so the finaltemperatures will be the same.III. The high reflectivity of the aluminum foil over casserole 2will suppress heat loss by radiation, while the heat lossesby conduction and convection for casseroles 1 and 2 will besimilar.

A spherical brass shell has an interior volume of 1.55 x10-3 m3. Within this interior volume is a solid steel ball thathas a volume of 5.00 x 10-4 m3. The space between the steel ball and the inner surface of the brass shell is filledcompletely with mercury. A small hole is drilled through the brass, and the temperature of the arrangement is increasedby 10 °C. What is the volume of the mercury that spills out of the hole?

A homeowner is unhappy with her heating costs. One wall of her house is 4 meters tall and 8 meters wide and has no windows, and it is made of brick and mortar with a thermal conductivity of 1.0 W m K . It is 40 cm thick. The house is heated to a temperature of 20 ◦C inside. (a) What is the rate of heat loss through the wall on a day when it is 0◦C outside? (b) A layer of rock mineral wool, which has a thermal conductivity of 0.032 W m K is to be installed on the interior surface of the brick wall. How thick should the layer be to lower the rate of heat transfer through this wall to half its original value? (c) If the rock mineral wool is instead installed on the outer surface, is the thickness required the same?

In this example we see how thermal expansion can actually throw off the accuracy of a length-measuring device-namely, a tape measure. A surveyor uses a steel measuring tape that is exactly 50.000 m long at a temperature of 20 °C. What is its length on a hot summer day when the temperature is 35 °C? SOLUTION SET UP AND SOLVE We have Lo = 50.000 m. To (Note that because AL is usually much smaller than Lo, we need steel is 1.2 x 10-5 K-¹. Using the same equation, The new length is Part A - Practice Problem: 20 °C, and T 35 °C. We use the following equation to find AL: AL=aLo AT IVD ΑΣΦ Submit L = Lo + AL 50.000 m -0.0090 m : 50,009 m REFLECT The measuring tape lengthens by 9 mm, or 0.018%. In surveying a baseball field, this amount is negligible, but not when measuring the length of a steel bridge. Note that, although Lo is given to five significant figures, we need only two of them to compute AL. Request Answer keep more significant figures in the lengths than in the temperatures.) The…

Hi there! Can you help em figure this problem. I keep gettign 707 watts and that is not correct. Seals may cool themselves by using thermal windows, patches on their bodies with much higher than average surface temperature. Suppose a seal has a 0.030 m2 thermal window at a temperature of 30∘C. If the seal's surroundings are a frosty -15 ∘C, what is the net rate of energy loss by radiation? Assume an emissivity equal to that of a human. Express the answer in watts. Thank you for the help! It is appreicated.