In the article "Preparing for Aluminum GTAW" by Frank Armao, what are the author's recommendations for preparing aluminum base metal for welding ?
I

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length