An explorer walks into a lab in a science building. She has a compass in her hand and finds that the south pole of her compass points toward the room's East wall when she is nearer that wall and toward the west wall when she is nearer that wall. You could explain this if magnetized metal had been installed in the East and West walls with North poles pointing into the room. If no magnetic material
was installed in the North or South walls of the room, she would expect that
a. the south pole of the compass would tend to point toward those walls.
b. the north pole of the compass would tend to point toward those walls.
c. the compass needle would not point in any particular direction.
d. the north pole of the compass needle would tend to point toward the centers of those walls, but the south pole would tend to point toward the sides of those walls.
e. the south pole of the compass needle would tend to point toward the centers of those walls, but the north pole would tend to point toward the sides of those walls.
b
You might also like to view...
The intensity of sunlight falling on the earth is about 1.4 kW/m2 (before any gets absorbed by our atmosphere). At what rate does the sun emit light energy?
(The earth-sun distance = 1.5 × 108 km and the earth's radius = 6.4 × 103 km.) A) 4.0 × 1026 W B) 3.2 × 1022 W C) 7.2 × 1014 W D) 7.6 × 108 W
The lunar mare radioactively date back to 4.6 billion years, at the origin of the Moon, hence their dark color due to this aging
Indicate whether the statement is true or false
A heater is rated at 1200 watts for a 120-volt source.The resistance of the heater is __________
Fill in the blank(s) with correct word
Calculate the Nusselt number and the convection heat transfer coefficient for water at a bulk temperature of 32°C flowing at a velocity of 1.5 m/s through a 2.54-cm-ID duct with a wall temperature of 43°C. Use the Gnielinski correlation and two other correlations given in te text and cmpare the results.
GIVEN
• Water flowing through a duct
• Bulk water temperature (Tb) = 32°C
• Water velocity (V) = 1.5 m/s
• Inside diameter of duct (D) = 2.54 cm = 0.0254 m
• Duct wall surface temperature (Ts) = 43°C
FIND Use three different methods to find (a) The Nusselt number (NuD)
(b) The convective heat transfer coefficient (hc)
ASSUMPTIONS
• Steady state
• Fully developed, incompressible flow
SKETCH
PROPERTIES AND CONSTANTS
for water at a reference temperature equal to the bulk temperature (Tref = 32°C)
Thermal conductivity (k) = 0.619 W/(m K)
Kinematic viscosity (?) = 0.773 × 10–6 m2/s
Prandtl number (Prb) = 5.16
Absolute viscosity (?b) = 763 × 10–6 (Ns)/m2
Prandtl number at surface temperatue(Prs) = 4.06 At the surface temperature of 43°C:
Absolute viscosity (?s) = 626.3 × 10–6 (Ns)/m2