Labor rates must take into account both the base labor paid to teh mechanic plus the following factors: 1  Mechanics overhead costs - hand tools he usually has to provide. 2  Shop overhead including many consumables, lights, compressors, ramps, lifts, large equipment like alignment and diagnosis tools, cleaning facilities, bathrooms and water.
A wave is a way in which energy travels from one place to another. There are many kinds of waves, such as water waves, sound waves, light waves, radio waves, microwaves and earthquake waves. All waves have some things in common.
Secondary waves (also called shear waves, or S waves) are another type of body wave. They move a little more slowly than P waves, and can only pass through solids. As S waves move, they displace rock particles outward, pushing them perpendicular to the path of the waves.