White dwarfs were once the cores of stars that produced planetary nebulae
Indicate whether the statement is true or false
TRUE
You might also like to view...
Carbon dioxide at 427°C is to be used to heat 12.6 kg/s of pressurized water from 37°C to 148°C while the gas temperature drops 204°C. For an overall heat transfer coefficient of 57 W/(m2 K), compute the required area of the exchanger in square feet for (a) parallel flow, (b) counterflow, (c) a 2-4 reversed current exchanger, and (d) crossflow, gas mixed.
GIVEN
• CO2 heating water in a heat exchanger
• CO2 temperatures
? Tg,in = 427°C
? Tg,out = 427 – 204 = 223°C
• Water temperatures
? Tw,in = 37°C
? Tw,out = 148°C
• Water flow rate ( m w)= 12.6 kg/s
• Overall heat transfer coefficient (U) = 57 W/(m2 K)
FIND The area (A) required for:
(a) parallel-flow (c) A 2- 4 reversed current exchanger
(b) counterflow (d) Crossflow, gas mixed
ASSUMPTIONS
• In configuration (c), the gas is in the shell side
SKETCH
PROPERTIES AND CONSTANTS
the specific heat of water at the mean temperature of 92°C (cpw) =4205 J/(kg K)
In the context of the triangulation method, to find the distance to a star, astronomers use a very long baseline, which is _____
A) the size of Earth's orbit B) the diameter of Earth's orbit C) three times the radius of Earth's orbit D) double the size of Earth's orbit
Identical point charges Q are placed at each of the four corners of a 3.0-m × 4.0-m rectangle. If Q = 40 ?C, what is the magnitude of the electrostatic force on any one of the charges?
A. 3.0 N B. 2.4 N C. 1.8 N D. 3.7 N E. 2.0 N
1020 steel contains _________weight percent carbon.
Fill in the blank(s) with the appropriate word(s).