Please help me out on this... Only dogs
Only reptiles
Both cats and dogs
Both amphibians and reptiles

Explain vector addition, triangle method and parallelogram method

Aknife blade is a(n) a. lever b. screw c. wedge d. inclined plane

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.