Two thin converging lenses A and B have focal lengths fA and fB, respectively. Lens A has a shorter focal length than Lens B. A collimated laser beam travels down an optical axis from left to right. How must the two lenses be arranged on the optical axis so that the laser beam emerges from the pair of lenses collimated with an increased diameter

Which two particles are found in the center of an atom

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.

Aperson touches a large chunk of ice with their hand and remarks, “this is making me cold.” explain what this person is feeling. is the ice transferring “cold” to the person? is there a heat transfer occurring? explain.