In 1963, maarten schmidt of the california institute of technology found the most distant object that had ever been seen in the universe so far. called 3c273, it emitted electromagnetic radiation with a power of 2×1013 suns, or 100 times that of the entire milky way galaxy! schmidt called 3c273 a "quasi-stellar radio source," a name that was soon shortened to "quasar." since then, astronomers have found many quasars, some substantially more powerful and distant than 3c273. quasar 3c273 is moving away from earth at about speed 0.16c. the sun is 1.5×1011mfrom earth and emits energy at a rate of 3.8×1026j/s caused by the conversion of 4.3×109kg/s of mass into light and other forms of electromagnetic energy. the hubble constant is
h=70.8km/smpc=70.8103m/s3.09×1022m= =22.9×10−19s−1
estimate the mass of 3c273 that is converted to light and other forms of radiation each minute. by comparison, the mass of earth is 6×1024kg.

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?