The expected life of a ball bearing subjected to a load of $$9800N$$ and working at $$1000RPM$$ is $$3000$$ hours. What is the expected life of the same bearing for a similar load of $$4900$$ $$N$$ and a speed of $$2000rpm$$

Weldments in fabricated steel beams are designed for

A ductile material having an endurance limit of $$196$$ $$N/m{m^2}$$ and the yield point at $$294$$ $$N/m{m^2}$$ is stressed under variable load. The maximum and minimum stresses are $$147$$$$N/m{m^2}$$ and $$49$$$$N/m{m^2}$$. The fatigue stress concentration factor is $$1.32.$$ The available factor of safety for this loading is

The hole $${40^{\matrix{ {0.020} \cr { + 0.000} \cr } }}$$ & shaft, $${40^{\matrix{ { + 0.010} \cr { - 0.010} \cr } }}$$ when assembled will result in