Gimme shelter roofers maintains a file of past customers, including a customer number, name, address, date of job, and price of job. it also maintains a file of estimates given for jobs not yet performed; this file contains a customer number, name, address, proposed date of job, and proposed price. each file is in customer number order. design the logic that merges the two files to produce one combined file of all customers whether past or proposed with no duplicates; when a customer who has been given an estimate is also a past customer, use the proposed data.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.