Afocal arrangement that has a thin lens that the light passes through before traveling down the tube to the objective mirror is a
a. cassegrain focus
b. newtonian focus
c. schmidt-cassegrain focus
d. schmidt focus

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.

Photons with the highest energy have the longest period

How is the acceleration of an object in uniform circular motion constant? a - in magnitude only b - in direction only c - in both magnitude and direction d - in magnitude, direction & orientation