2018 RETA Breeze May- June

and width is the short dimension. So, a plate 8”x 10”, the 10” would normally be considered the length and the 8” would be considered the width. In most calculations it doesn’t matter which is which. When calculating area, a plate 10” long and 8” wide has the same area as a plate 8” long and 10” wide. Both have an area of 80 square inches. Area is used for at (2 dimensional) measurements. If we wanted to know how big the oor was we would multiply the width by the height. For this calculation, we don’t care how thick the oor is. Let’s try a few. (Answers to the questions are at the end of this article). 1.1 We are moving in a new wrapping machine, it is 8’ wide. e door way is 6’ wide. Will it t? 1.2 We’re getting ready to paint the engine room oor, the room is 130’ long x 35’ wide. Each gallon of paint covers 1500 sq. . How many gallons of paint will we need? 1.3 We need to store 13 pallets (4’ x 4’) in a room, the pallets cannot be stacked. e room is 22’ wide and 31’ long, can the pallets t? Sometimes, we need to know cubic feet instead of square feet. 1.4 We have purchased 24 presents for the company picnic. Each present is 8” wide, 14” long, and 3” high. e only place to store the presents until the party is in the plant managers coat closet. e coat closet is 27” deep, 18” wide and 4’ tall. Will the presents t? 1.5 e engine room is 60’ long, 35’ wide and 20’ tall. How many cubic feet is that? Not everything has a length and width. ere are times we need to determine the circumference or the area of a circle. Book I discusses this beginning on page 1-8. e circumference (or distance around) is calculated by multiplying the diameter by π (Pie) (3.1416). is can be very useful in the engine room. 1.6 e Pulley Problem, If the diameter of a pulley is 14”, what is the circumference? In these calculations we determine the volume by multiplying the length x the width x the height.

1.7 A piece of stainless steel tubing is struck by a forkli and bent. How do we determine the size of the tube? Well chances are we could guess reasonably well. To calculate it, we measure the circumference. e circumference is 4.7124” What is the OD of the tube? Pipe sizes become a little more complicated because the outside diameter is not a nominal number. e following chart shows outside diameters of several nominal pipe sizes.

1.8 An operator discovers a bent pipe and needs to order a replacement. Again, most experienced operators can make a fairly accurate guess, but why risk it when the calculation can be done quickly. e operator measures the circumference of the pipe at 20.81” What is the pipe size? 1.9 A new water pipe (1” Schedule 40 A53) is being run through the engine room wall. e operator must drill a hole through the wall to accommodate the new pipe. What size hole saw should be used? Areas of circle are calculated utilizing the radius multiplied by the radius, multiplied by pie. We show it as R x R x 3.1416 or R2 π. For instance, a 6’ diameter circle would have a circumference (distance around of 226 inches ((6 x 12) x 3.1416) and an area of 28.27 cubic feet (3’ x 3’ x 3.1416) Continued on page 14

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