One integrated circuit design calls for the diffusion of arsenic into silicon wafers; the background concentration of as in si is 2.5 × 1020 atoms/m3. the predisposition heat treatment is to be conducted at 1000°c for 45 minutes, with a constant surface concentration of 8 × 1026 as atoms/m3. at a drive-in temperature of 1100°c, determine the diffusion time required for a junction depth of 1.2 μm. for this system, values of qd and d0 are 4.10 ev and 2.29 × 10−3 m2/s, respectively.

Astudent is performing an experiment comparing sound and light waves. the student gathers the following data. what conclusion does the student most likely make based on this data? light waves always travel the same speed; however, the speed of sound is determined by the medium that it travels through. all sound waves always have the same energy, so the temperature of the medium does not affect wave speed. light needs to vibrate particles, so it travels fastest in tightly packed solids, while sound does not need a medium, so it travels fastest in a gas. tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

Which of the following examples illustrates static friction? a box sits stationary on a ramp. a ball rolling on the lawn eventually comes to rest. a car rounds a curve on a road. a fish swims upstream.