On average, the stars in elliptical galaxies are older than the stars in spiral galaxies
Indicate whether the statement is true or false
TRUE
You might also like to view...
A cooling system is to be designed for a food storage warehouse for keeping perishable foods cool prior to transportation to grocery stores. The warehouse has an effective surface area of 1860 m2 exposed to an ambient air temperature of 320C. The warehouse wall insulation (k = 0.17 W/(m K)) is 7.5 cm thick. Determine the rate at which heat must be removed (W) from the warehouse to maintain the food at 4°C.
GIVEN
• Cooled warehouse
• Effective area (A) = 1860 m2
• Temperatures
? Outside air = 32°C
? food inside = 4°C
• Thickness of wall insulation (L) = 7.5 cm = 0.075 m
• Thermal conductivity of insulation (k) = 0.17 W/(m K)
FIND
• Rate at which heat must be removed (q)
ASSUMPTIONS
• One dimensional, steady state heat flow
• The food and the air inside the warehouse are at the same temperature
• The thermal resistance of the wall is approximately equal to the thermal resistance of the wall insulation alone
SKETCH
Suppose that the build-up of fatty tissue on the wall of an artery decreased the radius by 10%. By how much would the pressure provided by the heart have to be increased to maintain a constant blood flow?
What will be an ideal response?
What is a major limitation in the Doppler method for detecting extrasolar planets?
A) it is better at finding massive planets like Jupiter rather than small planets like the Earth B) it is best suited to finding planets which orbit relatively close to their star C) it requires the use of fairly large telescopes and long exposures which limits the number of star that can be studied D) all of these are major limitations
Which of the following is NOT an example of a psychographic characteristic?
A. social group affiliations B. educational level C. lifestyle choices D. political affiliations