Two ball bearings from different manufacturers are being considered for a certain application. bearing a has a catalog rating of 3.0 kn based on a catalog rating system of 3 000 hours at 500 rev/min. bearing b has a catalog rating of 5.0 kn based on a catalog that rates at 106 cycles. for a given application, determine which bearing can carry the larger load.

May someone explain how to do this question?

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.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?