Weights And Measures (1954)

[Music] [Music] [Music] come on dad let's get the train set up just a minute Tommy what are we ever going to stop figuring and measuring things and start doing things I want to P before I leave for Uncle Bill's Farm if you're ever going to be an engineer Tommy you'll have to use figures and measures every day if an engineer doesn't do anything but measure things and figure things on paper I don't want to be an engineer even if you are one listen son you wouldn't even have an electric train if people didn't measure things you wouldn't have good food to eat a nice bed to sleep in a home to live in or a basement to set up electric train in you couldn't even have sports you like football well where would football be without measurements you like track well you measure things in track like how far a broad jumper jumps and how high a pole valter goes and how fast a runner runs in most sports the equipment the balls shot puts bats and clubs are carefully weighted you can't really get along in this world unless you understand weights and measures now take your electric tray you'd like to put it on a plywood base wouldn't you well how much plywood you need read the specifications the base should be 8 ft by 4T well let's see if we have enough room uh lay it out on the floor I'll hold the tap 1 2 3 4 5 6 7 8 that's right isn't it yes you've measured the length now measure the width 1 2 3 four okay mhm you've been using a linear or line unit of measurement see 8 ft and 4T now you know the length and the width now you can use a new unit of measure the surface or area of your base how will I figure that to measure length and width you used a line measure it told you how long and how wide the plywood should be but to figure out the surface of the board you'll need another type of measure a surface or area measure try to imagine that there are lines drawn foot by foot across the length and width of your base there would be squares all over the drawing right four squares in each row eight rows of squares all together 8 * 4 or 32 squares each 1T Square in size in other words the area of your plywood base measures 32 square ft okay son now we'll call the lumber yard and see how much they charge for a square foot of ply with then you go and get packed for your trip to Uncle Bill's Farm out at his uncle's Farm Tommy finds a lot more reasons for understanding weights and measures just now Tommy's uncle is taking out a field for a new Orchard he'd like it to be one acre in size the acre is a measure for large areas like fields or Orchards it takes a large number of square feet 43,560 to tell the size of one acre that's why we measure large surfaces of land and Acres rather rather than in square feet to compare an acre with something we're all familiar with let's look at a football field the football field is just 1/3 larger than the orchard in other words a football field is about 1 and 1/3 acres in area oh but Farms are much larger Uncle Bill's Farm is about 160 acres in area and that's room enough for more than a 100 football fields well now that Tom has had some experience with figuring surfaces he can help his uncle with another problem his uncle wants to know whether this bin is large enough to store feed grain in it for his cows the bin is shaped like a large Cube how will Tom figure out its volume remember Tom measured length in linear feet surface in square feet and volume he'll measure in cubic feet this is 1 cubic foot a cube 1T wide 1T long 1T deep how many such cubes does the bin hold on the bottom of the bin there's room for 6 * 5 or 30 cubes the bin is 4T deep which means that we can place four layers of Cubes into it in all the bin holds 4 * 30 or 120 1T cubes the volume of the bin is therefore 120 cubic feet of course Tom has no cubes to put into the bin in order to figure out the volume instead he'll use arithmetic first he figures out the size of the floor 6 ft * 5T is 30 ft 30 square ft is the floor area now the depth the bin is 4T deep Tom multiplies the floor area 30 square ft by the depth of the bin 4T and gets the volume 120 cubic feet this demonstrates that volume is the product of three dimensions while area is the product of two Dimensions Tom could apply his experience with figuring area and volume in many places for instance here at this building site a neighbor is building a house the for digging will be figured by the volume of earth dug Tom could easily figure out the cost he'd have to find the volume of the basement by multiplying the length by the width by the depth in the same manner he could figure out how much sand this truck can carry but sand is usually measured by weight Tom is curious he'd like to see how they weigh sand what a big scale it's made to weigh very heavy objects only if Tom stepped on it it wouldn't even show his proper weight first they weigh the empty truck see the numbers on the scale they go by the thousands this is the weight of the empty truck 8,000 lb when the truck is loaded with sand it's weigh again this is the weight of the truck and the sand £4,000 the contractor will have to pay for £6,000 or three tons of sand one ton you know is 2,000 lb we use tons instead of pounds for very heavy objects and when weighing by the ton we usually don't expect very precise weighing a few pounds of sand more or less won't matter but not all scales are as rough or coarse as truck scales driving to the post office with his Uncle Tom has a chance to see several other kinds of scales hi Bill so you got a new hand sure do this is my nephew Tommy how are you Tom hi do you've got a lot of skills in here sure we do we need them in our work what for oh lots of things you see this is a rough scale it's meant for weighing packages it weighs only pounds you mean Uncle Bill's package weighs 4 and2 lb that's right see we don't have to be any more accurate because we charge for packages by the full pound in this case your uncle will pay for full 5 lb instead of 4 and2 now for air mail we use this scale this scale is calibrated in ounces and half oz you know why because we charge air mail postage by the ounce and half ounz you mean different scales are used for weighing different kinds of meal is that it is that well that's about what it amounts to bill you got 66 cents sure do there fine SW let's go Tommy okay Salam see you later after the post office Tom and his uncle go shopping in the grocery store Tom learns more about weights while his uncle picks up a bag of potatoes Tom notices a man checking the grosser scale what are you doing with that scale checking it why is it broken it's my job inspecting weights and measures the inspector sees to it that I take all my monies with when I sh as many pounds of potatoes as I pay for and not less and no more either but why there are laws about weights and measures that tell us how accurate scales in measur should be some scales must be more accurate than others you take this scale here the acceptable difference in weight according to law must be no more than this much for the weight of that entire sack of potatoes for other measures other laws apply you may have seen how cloth is measured in some stores measuring clock should show no more than one4 in difference one way or another in the 100 ft of cloth the law tries to make sure that you get a fair deal when you go into a store that you get what you pay for and that the storekeeper does not lose any money because of folly weights and measures when I finish my work I put a seal on the scale to show you that this scale conforms to the law I thought scales were always right well if they were I wouldn't have any job haven't you got the train started yet Dad I've been waiting for you the plywoods arrived do you remember how you figured out how many square F feet we'd need sure do you know what I met an inspector of weights and measures did you give me a hand with this and tell me all about it the inspector was telling me something about accurate weights Dad how accurate do engineers have to be well remember the day I took you out to visit my new office of the aircraft plant there we assemble thousands of different parts and make airplanes out of them we buy the parts from 100 or more workshops and yet they fit together now in order to make them fit many kinds of very careful weighings and measurements have to be made our toolmakers have special measuring instruments gauge blocks calipers micrometers and surface gauges all designed for precise measuring now with a mccrometer for instance machine makers can measure as close as a few 10,000 of an inch and that is important when you make tools haven't I taken you to our research Department well of course I have there we use even finer measuring instruments some laboratory scales will weigh as little as 17,000 of an ounce for instance you could take a piece of paper and weigh it then write your name on it the analytical balance would indicate even the weight of one penciled word you told me you'd like to become a research engineer well if you do you learn to use such very sensitive measuring instruments however then you probably won't measure in pounds feet or yards but in meters and kilog scientists all over the world use the system it's an international measuring system that goes by T like our number system and therefore it's easier to use in figuring but we'll talk about that some other time okay now can we get the train going sure watching Tom we've seen several kinds of weights and measures in use but there are many more in the kitchen we use cups and spoons to measure flour sugar spices and other ingredients for cooking we buy milk and cream by the pints quarts gallons we often buy fruit by The Bushel our Maps tell us distances in Miles our electricity is measured in kilowatts our television sets are tuned to the microwaves and we tell the speed of modern jet planes by comparing it with the speed of sound but which kind of weight or measure or what size of unit we use always depends on the purpose of the measurement [Music]