What is the demand factor for three commercial ranges? ​

Tech a says never use a water hose to clean up dust after a repair. tech b says never use a floor scrubber to clean up dust after repairs. who is correct?

A75mm diameter shaft is supported in a journal bearing 75mm long with a diametral clearance of 0. 1mm. it supports a radial load of 1000 n and is lubricated with sae 50 oil at 70°c. find the friction torque and the power loss when the crankshaft rotates at 2900 rev/min.

Precipitation hardening can be achieved in many light alloys by a three-step heat treatment. what is carried out and what is the purpose at each step? why is such a treatment necessary based on the nucleation and growth theory of phase transformation. compare this treatment with tempering martensite for carbon steels (similarities and differences).