Which of the following is NOT a factor in determining whether a body in the solar system retains an atmosphere?
A) composition and weight of the gases
B) escape velocity
C) axial tilt
D) rotation rate
E) distance from the Sun
D
You might also like to view...
Design (i.e., determine the overall area and a suitable arrangement of shell and tube passes) a tubular-feed water heater capable of heating 2,300 kg/h of water from 210C to 90°C. The following specification are given (a) saturated steam at 920 kPa absolute pressure is condensing on the outer tube surface, (b) heat transfer coefficient on steam side is 6800 W/(m2 K), (c) tubes are of copper, 2.5 cm, 2.3-cm-ID, 24 m long, and (d) water velocity is 0.8 m/s.
GIVEN
• A tubular-feed water heater, condensing saturated steam on outside
• Water flow rate m w= 2300 kg/h = 0.639 kg/s
• Water temperatures Tw,in = 21°C Tw,out = 90°C
• Steam temperature = 920 kPa absolute
• Heat transfer coefficient on steam side h o= 6800 W/(m2 K)
• Tubes are copper Di = 2.3 cm = 0.023 m Do = 2.5 cm = 0.025 m
• Water velocity (V) = 0.8 m/s
FIND
• The transfer area (A) and a suitable arrangement of shell and tube passes
SKETCH
Assuming a single shell pass and two tube passes
PROPERTIES AND CONSTANTS
the thermal conductivity of copper at 127°C (k) = 392 W/(m K)
the saturation temperature of steam at 920 kPa (Ts) = 176°C
for water at the average temperature of 56°C
Density (?) = 984.9 kg/m3
Specific area (cpw) = 4181 J/(kg K)
Thermal conductivity (kw) = 0.653 W/(m K)
Kinematic viscosity (?) = 0.510 × 106 m2/s
Prandtl number (Pr) = 3.23
It takes 87 J of work to stretch an ideal spring from 1.4 m to 2.9 m from equilibrium. What is the value of the spring constant of this spring?
A) 27 N/m B) 77 N/m C) 52 N/m D) 39 N/m
A solid cylindrical bar conducts heat at a rate of 25 W from a hot to a cold reservoir under steady state conditions
If both the length and the diameter of this bar are doubled, the rate at which it will conduct heat between these reservoirs will be A) 200 W B) 100 W C) 50 W D) 25 W E) 12.5 W
If the displacement of an object is given in SI units by Dx = -5t + t 2, at t = 2 s its velocity and acceleration are, respectively: (Hint: Use dimensional analysis along with the equations for motion with constant acceleration.)
a. positive, positive. c. negative, negative. b. positive, negative. d. negative, positive.