Specific Heat: A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater magnitude gain or loss of heat during the time the system takes to reach thermal equilibrium?
A. the aluminum
B. the copper
C. Neither one; both of them experience the same size gain or loss of heat.
D. It is impossible to tell without knowing the masses.
E. It is impossible to tell without knowing the volumes.
Answer: C
You might also like to view...
Monochromatic light of wavelength 500 nm is incident normally on a grating. If the third-order maximum of the diffraction pattern is observed at 32.0°, what is the total number of maxima can be seen?
A) 5 B) 7 C) 10 D) 11 E) 8
Which resistor is in series with resistor R?
a.
R1
b.
R2
c.
R3
d.
R4
It is possible to hear an approaching train before you can see it by listening to the sound wave through the track. If the elastic modulus is 2.0 × 10^11 N/m2 and the density of steel is 7.8 × 10^3 kg/m3, approximately how many times faster is the speed of sound in the track than in air? (vair ? 340 m/s.)
a. 20 b. 5 c. 10 d. 15 e. 25
Water enters a double pipe heat-exchanger at 60°C. The water flows on the inside through a copper tube 2.54 cm ID at a velocity of 2 cm/s. Steam flows in the annulus and condenses on the outside of the copper tube at a temperature of 80°C. Calculate the outlet temperature of the water if the heat exchanger is 3-m-long.
GIVEN
• Water flow through a tube in a double pipe heat-exchanger
• Water entrance temperature (Tb,in.) = 60°C
• Inside tube diameter (D) = 2.54 cm = 0.0254 m
• Water velocity (V) = 2 cm/s = 0.02 m/s
• Steam condenses at (Ts) = 0.80°C on the outside of the pipe
• Length of heat exchanger (L) = 3 m
FIND
• Outlet temperature of the water (Tb,out)
ASSUMPTIONS
• Steady state
• Thermal resistance of the copper pipe is negligible
• Pressure in the annulus is uniform therefore, Ts is uniform
• Heat transfer coefficient of the condensing steam is large (see Table 1.4) so its thermal resistance can be neglected
• Outside surface of the heat exchanger is insulated
SKETCH
