Learning about buses with LEGO (Full Lesson)

Key Takeaways

should imagine if you have something like a hammer okay if I have a hammer and then I rested on its side okay you have a hammer and have a resting sideways like this and then I want to hold my hand under it to balance so that both sides are equally have equal weight and do I put my hand right in the middle of the hammer I'm just going to draw this out so so that you can you can see what I mean okay I'm gonna ask you this question so I have a hammer and I'm gonna put it on its side like that okay so this is a hammer and I've put it on its side and then I want to put my hand under it okay so that it's balanced on both sides when I put my hand right down the middle of off the hammer do I put my hand like this underneath under the hammer or where do I put my hand he wants to raise their hand and tell me ray are you clear on that Heaviside you put it under the heavier sign and check so you put it your hands probably closer to here right you put your hand under here and and hold it closer to the heavy side that's excellent right that is really really interesting because when you when you think about balancing something you would normally think about putting your hand or holding something if you want to balance something right in the middle of it right so for example if I have a beam like this beam like this and I wanted to have be balanced completely on both sides and put my hand whoops I might put my finger pretty much directly in the middle right and put my finger directly in the middle because that is that is going to be the the balancing point but for a hammer it's different why do you think we have to put our hand closer to the heavy part anyone anyone wants to want to have a guess why we would need to put our hand closer to the heavy heart when we are balancing not sure it is a special special word called center-of-mass okay so let's have a look at it it's a special word called Center of maths okay center-of-mass what is the center of mass of something the center of mass of any kind of object is the point at which you can balance that object okay and for a hammer it's much closer to the heavy part which is the head of the hammer if you try to balance your hand on the hammer on the lighter side then the hammer would just fall over because the center of mass for a hammer is right over here okay this is where the center of mass is okay this is the center of mass for a hammer that's going pretty good okay so the center of mass for a hammer is much closer to this heavy side okay and there are lots of really important things to realize when it comes to the center of mass of something for example when you have a center of mass that is really close to the ground it's very hard to push something over okay let me draw you another picture so if you imagine that we have the ground here okay we have the ground and then I'm looking at the front view of a car okay the front view of a car we got the winner will windows and here we go we got the win new windshield wiper yeah we got the front of this car it's quite low to the ground right and next to it we have a double-decker bus okay so we have a double-decker bus that is really really tall okay when these two cars will this current is bus when they're going around a corner who's more likely to fall over who do you think is more likely to follow then you want to put their hand up and have a guess which which they with the car be more likely to fall over would the bus be more likely to follow right the bus the bus why do you think the bus is more likely to fall over it's taller than the cache but most importantly that's excellent there right most importantly the reason that the bus is more likely to fall over is because of the center of mass the center of mass is higher on a bus especially a tall bus okay so especially trucks and buses that are really really tall they are much more dangerous going around corners because they can potentially fall over but in order for us to stop that from happening is we need to lower the center of mass okay so if you have a look at it have a closer look at our at our bus in downtown the cars center of mass is probably somewhere around here okay the center of mass of the car is something around you and for the bus it's a little bit higher it's probably some somewhere like here but if you make the bottom of the bus really really heavy and the top of the bus really really light then it is much less likely to fall over so we will try to make all the weight go down to this crime of the bus okay to make all the heavy parts of the bus be really really low on the bus that way when we are going around corners it is a lot less likely to fall over I want you to build a bus but it has to be a tall bus okay with the pieces in your kit and I want you to use as many pieces as you can in the next 15 minutes build the bus as tall as you can not just long I don't want too long bus I wanted tall bus but the most important thing is I want you to add distance okay this black piece must be on your bus and then at the end I'm going to ask everyone where did you put this black piece and why okay so spending about 15 minutes now building your bus and make sure that you put this black piece inside I'm going to be building the bus - okay you have a question raise your hand you they're gonna start building a bus as well doesn't have to be long it just has to be really taut okay and it's the point of the exercises we need at all bus and you don't have to copy my bus can be any kind of question you want you can build it however you like three minutes if you have a question you let me know I'm gonna get started with maybe the base of the bus you you this idea of the buses it has to be really tall so make the bottom not too long so that we can spend more time building a really tall bus you you you you you you you you you you you you you you you you that's everyone's bus going then I put some wings on my bus as well make it look good you you you you you you you you you you you you know another 10 more minutes building okay and at ten you you you you you you you you you you you you you you you this is my bus going alone you you have more Lego figures than you can put more different Lego people inside your bus as well so you have more people in the bus this is a bit wobbly for me you you you you there's our bus going raise your hand if you have a problem okay but feel free to build your own bus make sure it's as high as you can make it that one's not super high maybe you can make yours even higher you you you you you you you you you this is going to be my little bus like I said you look anything could be okay so how is everyone going with the bus so far so let me show you just my bus for a little bit and you guys can keep on building your buses if you like okay so here I have a bus with four wheels so each wheel is using the white connectors to connect the wheels together and then I'm using a bunch of beams to layer on top of each other to become the side of the bus and then down the bottom of the bus I keep a really really dense so and when I have a dense like this it means that it gets it's going to be very very heavy down underneath because remember when we talked about the designing a bus we need to make sure that the bottom of it is really really heavy and the top of it is really really light so we want to make sure that the top of your bus is going to be very very light compared to the bottom of your bus so when it comes to putting this black break in I want you to have a go of doing it like this okay you can put your black brick right on the top of the bus you like this and then you can try to tip it over and you'll find that it's going to be very easy to tip over see that does that make sense if I put my black brick right at the top of the bus its put my center of mass all the way up closer to the top because it's much heavier at the top just like a hammer remember the hammer the center of mass is close to where the heavy part of the hammer is and with the bus it is the same thing if we put the heavy stuff on the top of the bus then it's going to be really unbalanced and it's going to be really easy to push over and fall over like this okay so that is why when you are putting your bus together you should put your heavy brick towards the bottom of your bus okay and try to slide it in somewhere where where it's going to be as low to the ground as possible for example for me I can put it down here yes and if you put it down inside under into the bottom of the bus it's a lot harder to push over okay and of course it still falls over but it's much harder to follow and then if I had put the brick on top of the bus like this okay if I put the brick on top of the bus it's going to be very easy to fall over that makes sense so make sure that when you are designing your bus to put your black brick close to the middle and close to the bottom of your bus that way it keeps it a lot more stable and you can go around corners better right any question no question I haven't gone really high I have decided that because that's the minifigures who are on b1 level which means I have changed my mind and you like the connector Oh so dad thanks Lucas on that looks more like two levels yeah that's a great idea right so that's a good use of connectors as well have you put in your black brick as well did you put it close to the bottom of your bus as close to the bottom as possible yes yeah very good and did you see the difference how it's much harder to push over now compared to if you're very good so remember the key word from today is center of mass okay because that is the most important thing to realize for this lesson is that we are learning about center of mass and how to make things more more stable by putting the weight towards the bottom okay so as close to the ground as possible well then all right fantastic guys so that is the end of our lesson today if you have any more questions feel free to ask mom and dad just send me an email or give me a call okay my name is Gary I'll talk to you again next week okay