What is the Fermi energy?
a.
Near T = 0, the Fermi energy indicates the maximum energy level occupied. The Fermi energy is useful in understanding the Fermi-Dirac distribution and also when applied to the problem of electrical conduction.
You might also like to view...
What surprised scientists to learn about Mercury from MESSENGER's data? a. Mercury is still geologically active with molten lava flows on the surface. b. Mercury does have an atmosphere causing some erosion of the surface. c. Mercury has significantly more craters than the Moon
d. Mercury has a magnetic field despite its size. e. Mercury is rotating faster than earlier predicted.
The density wave theory explains spurs and branches along the spiral arms
Indicate whether the statement is true or false
Assume that the water is originally at the freezing temperature Tf, that the cooling medium inside the tube surface is just below the freezing temperature at a uniform temperature Ts, and that ho is the total heat transfer coefficient between the cooling medium and the pipe-ice interface. Also show the thermal circuit.
Show that the dimensionless equation for ice formation at the outside of a tube of radius ro is
where
GIVEN
? Water freezing on the outside of a tube
? Tube radius = ro
? Cooling medium temperature = T ? (uniform)
? Heat transfer coefficient between the cooling medium and the pipe-ice interface = ho
FIND
? Draw the thermal circuit and show that the dimensionless equation for ice formation is as shown
above
ASSUMPTIONS
? Steady state
? The thermal capacitance of the ice layer is negligible
? T? is constant
? The water is at the freezing temperature, Tf
? The properties of the ice are uniform
SKETCH
A 0.28-kg stone you throw rises 34.3 m in the air. The impulse your hand receives from the stone while it throws the stone is
a. 2.7 N s, up. b. 2.7 N s, down. c. 7.3 N s, up. d. 7.3 N s, down. e. 9.6 N s, up.