You would like to freeze a surgically removed 5.0 cm diameter spherical brain tumor. in order to avoid the formation of large ice crystals within the tumor, you would like to keep the temperature within the tumor spatially uniform. tissue properties: constant thermal conductivity = 0.64 w/m*k, thermal diffusivity = 2.5 x 10-7 m2/s. (a) determine an appropriate h in order to meet this criteria. (b) how long will the tumor take to freeze, i. e. reach 0°c, if placed in a -20°c freezer using the h found in part (a).

Which of the following are not typically included in the periodic table? a. atomic mass b. element symbol c. isotopes d. number of electrons

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)