Answer Happy

1. The two properties that determine an object's luminosity are its temperature / density and its mass / area. Of the two properties, the one that contributes most to the object's luminosity is temperature / density / mass / area. 2. The luminosity of a 6 foot tall man is greater than the same as / less than the luminosity of a 3 foot tall child because the man's temperature is higher than / the same as / lower than the child's temperature, and the man has a larger / the same / a smaller surface area. 3. The luminosity of a stadium light according to someone inside the stadium will be greater than the same as / less than the luminosity according to someone in a distant parking lot, because the luminosity of an object depends on / does not depend on the distance to the observer. 4 When an engine is first started its temperature is higher than / the same as / lower than its temperature after it has been running for a while. As a result, the engine's luminosity is greater / the same / less when it is first started. 5. Star Z is 10,000 times brighter than the Sun and has a temperature of 3500K, while Star Y gives off less than 1/10th the Sun's energy output but is nearly 20,000K. Which is larger,