Solid state physics, thermodynamics, statistical mechanics [40 points] there isa semiconductor with two bands: the lower band is described by e(k), the upper band by eo-e(k). the two bands are separated by an energy gap of 24 (hint: use electron-hole symmetry. this is also evident from the way the upper band is defined.) a. calculate the chemical potential as a function of the temperature. [20 points 3. b. examine whether the system can be treated using classical statics at low temperatures. 20 points

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.

A2.0 μf capacitor and a 4.0 μf capacitor are connected in series across a 0.827-kv potential. the charged capacitors are then disconnected from the source and connected to each other with terminals of like sign together. find the voltage across each capacitor.

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?