A modern version of Joule's experiment has you turn a crank attached to an 85.0 g aluminum cylinder. A belt exerts a frictional torque on the cylinder of 1.50 Nm. The specific heat of aluminum is 900 J/(kg•K)
How many turns of the crank are necessary to raise the temperature of the aluminum by 40 C°? A) 325
B) 650
C) 900
D) 975
E) 1300
A
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A pipe of diameter three cm is replaced by one of the same length but of diameter six cm. If the pressure difference between the ends of the pipe remains the same, by what factor is the rate of flow of a viscous liquid through it changed?
a. 2 b. 4 c. 8 d. 16 e. 32
Two current loops are coaxial and coplanar. One has radius a and the other has radius 2a. Current 2I in the outer loop is antiparallel to currentIin the inner loop. The magnitude of the magnetic field at the center of the two loops is
A.
B.
.C.
.D.
.E.
.Two 3-? resistors are connected in series. Another 3-? resistor is then connected in parallel to the two already in series. The resulting combination has what resistance?
1. 1 ? 2. 2 ? 3. 4 ? 4. 5 ?
The top of a 30 cm I-beam is maintained at a temperature of 260°C, while the bottom is at 93°C. The thickness of the web is 1.25 cm. Air at 260°C is blowing along the side of the beam so that h= 40 W/(m2 K). The thermal conductivity of the steel may be assumed constant and equal to 43 W/(m K). Find the temperature distribution along the web from top to bottom and plot the results.
GIVEN
FIND
The temperature distribution along the web and the plot the results
ASSUMPTIONS
The thermal conductivity of the steel is uniform
The beam has reached steady state conditions
One dimensional through the web
The beam is very long compared to the web thickness
SKETCH
