Moving Things On Land (1958)

bad for gym but what's bad for gym is good for Bobby Cooper he's trying to get a nice big collection of comic books he is that is if they can solve an unpleasant little transportation problem however something called friction seems to be holding things up wouldn't this be a wonderful world if suddenly there were no friction to hold things back just imagine a box of comic books would slide down a driveway as though the driveway were slippery er than iron but just thank all of the shoelaces in the world would suddenly come untied and all of the houses would start to fall apart everything would yield slippery even sandpaper imagine the things that you wouldn't be able to hold think of the meals that would slide off tables think of the people who wouldn't be able to get into their houses people who were stopped couldn't get started and people who were started couldn't stop at least bro ha what is it it keeps this box from sliding downhill you think of pavement as being fairly smooth when you look at it closely you find that rough little bumps cover the surface in the wooden box there are bumps and hollows and splinters too the rougher two surfaces are the more the rough places and the heavier the load the more the rough places catch at each other this catching and dragging is friction though friction can be useful Jim and Bobby sometimes wish they didn't have quite so much of it people have to overcome friction every time they move something from one place to another and everything that you have has been moved from someplace else everything in your house the things your house is made of everything in a city except the earth it stands on has been moved there from someplace else moving things is so important that many people have worked at ways of making moving easier and faster what are some of the ways the boys might use to make their moving job easier let's give them some runners aha easier there's less friction because the runners are smoother than the box and there are fewer rough places to catch on the pavement there would be still less friction if we could smooth the paving - let's do something else for the boys let's sprinkle some powdered soap on the driveway that smooth it a little easier yet smoothing the road all the way to Bobbie Cooper's house would take a lot of soap but we make many things easier to move by making surfaces smooth let's give Bobby and Jim something to make their moving job still easier something they can use for rolling the Box move so easily now that it hardly needs to be pulled usually there is much less friction when things are moved by rolling rather than by sliding however there's a problem about moving things for any distance on rollers someone has to keep bringing rollers up to the front of the load wouldn't our highways look strange if a person were out busily putting rollers in front of each car and truck rollers are sometimes used to move things when distances are short more often the rollers are fixed in place and the load is moved over them and sometimes of course things are moved by rolling when they are themselves rollers if we're really going to help transport those comic books we'd better give the boys some rollers that will stay attached to the load instead of full-length rollers we'll give them four thin rollers now we'll attach two axles under the crate and put on the rollers and maybe we'd better stop this talk about rollers and begin calling them wheels now we have a new problem we've cut down the friction against the ground but we have friction in a new place here where the rough axle rubs against the rough wood of the wheel of course there's much less friction than pulling without wheels at all but there's still plenty this is the way many carts used to be made there's so much rubbing between this kind of wheel and axle that the cart is hard to move the rubbing wears away small pieces of wood and finally the axle may break the boys job would be easier if we gave them axles and wheels made out of metal [Music] metal is harder and can be made smoother so there's less friction between the axles and the wheels but even metal has little rough places that you could see only with a microscope so you can't see the rough places you can hear them rubbing and the friction slows the wheel down quickly there'll be less friction if we can cover the surfaces with something to keep them from touching ah just what we were looking for an oiled wheel works better because the oil fields the tiny bumps and there's less friction now listen and see how much longer it turns and now I suppose you think we ought to let the boys get along with their load of valuable literature not yet we're going to give them some wheels that are even better ball bearing wheels in this kind of wheel a ring of steel balls keeps the wheel from rubbing against the axle the wheel turns on the balls and the balls roll around the axle and of course oil helps at the same time whenever you see a wheel or a machine that runs smoothly and easily you can be fairly sure that the moving parts run on ball bearings or roller bearings now let's get this load on the road but this time let's do it in style Jim is going to be able to use friction if he needs to stop and Bobby has to use friction to help him get started but they've removed most of the friction between the load and the ground wheels like these are one of the best solutions that people have found for moving things on land I suppose you think that now the boys are going to settle down to a quiet afternoon of reading comic books don't you believe it Bobby's mother isn't going to let the comic books in the house either and after all we've done to help them a fine thing [Music]