Aspeaker that emits sound is located at the origin of a coordinate system. two microphones are located on the x-axis, with microphone 1 at the x = 3.0 meter mark and microphone 2 at the x = 5.0 meter mark. if the speed of sound is 343 m/s, how much longer does it take a sound emitted by the speaker to reach microphone 2 than microphone 1?

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.