Question1

A race car starts from rest on a circular track of radius 407 m. The car's speed increases at the constant rate of 0.490 m/s2. At the point where the magnitudes of centripetal and tangential accelerations are equal, find out the following. 

(a) speed of the race car 1 m/s 

(b) distance traveled 2 m

(c) elapsed time 3 s

Question2

The electrons in a example of n-type GaAs are frozen out on their donor levels by decreasing the temperature. Contacts are functional to sample and photoconductivity is then measured by exciting the electrons back into the conduction band with far-infrared radiation.

(a) Elucidate the spacing between peaks, the temperature dependence and the merging of the spectra at high energies.

(b) If the effective mass is 0.0665m, what is dielectric constant?