# AMASE: Stability

Posted on Monday, June 29th, 2020

#### Video Transcript

[Outside in a field two horses are walking in a pen.]

Mara: This little cutie is Benny and that's his mama, Jelly. We took this video when the little guy was just three days old. On today's ask me anything science edition we're going to talk about how it's possible for newborn animals to run around just after they're born it's crazy!

Joanne: It is pretty crazy when you think about it.

[Cut to Mara and Joanne sitting at the kitchen bar.]

Joanne: Especially when you realize that it takes humans almost a whole year before we're able to stand up all by ourselves and walk around. Why do you think it takes us so much longer?

Mara: Ah, were slow learners?

Joanne: That's one way of looking at it or we can look at these straws and connectors here and think about some key differences between people and horses.

[Joanne and Mara look at some simple straw/connector models. One with four legs and one with two legs. Each are sitting on a piece of coloured paper.]

Mara: That’s horses?! [Mara points to the model with four legs.] That’s people [Mara points to the model with two legs.]

Joanne: That right that's horses, that's people. What's a very important difference between those two?

Mara: Oh! Horses have four legs and people have two.

Joanne: Right so little Benny here, as long as he keeps his weight over this big rectangle [Joanne indicated the paper that the model is sitting on.] which is created by the points where his feet touch the ground he's stable. People on the other hand we have a much smaller rectangle of support for our weight so if our weight tips a little bit forward or a little bit backwards we're not stable when we fall down.

Mara: So, horses are more stable because they have more legs?!

Joanne: Yeah. They have more legs and they create a bigger area of support for their weight. So, come on, over here we're gonna demonstrate what happens if you move your weight around over your support. [Mara looks sceptical] No, don't worry I'm not gonna make you fall.

[Music.]

[Cut to Mara standing against a brick wall with a piece of paper centered above her head.]

Joanne: Okay Mara's standing here with a piece of paper marking the center of her body with her feet both flat on the floor. Now she's gonna lift up one foot and you see she has to lean over a little bit so that her weight stays over that support. Now she puts her foot back down comes to the middle lift up the other foot and she's got to lean the other way in order to be balanced to keep that weight over her support.

[Mara turns with her side to the brick wall. With the paper roughly in the middle between front and back.]

Joanne: Okay now Mara's gonna demonstrate what happens when she wants to stand on her tiptoes. Mara what do you think is gonna happen?

Mara: I think I am going to have to lean forward.

Joanne: Alright let's see what happens ready three two one alright and as predicted when Mara leans forward to stand on her tiptoes she has to lean forward a little bit in order to keep her weight over the support. Nice job!

[Mara is standing facing the wall.]

Joanne: And now Mars gonna demonstrate something that you can try at home with your hands behind your back and your toes and your nose touching the wall try and stand on your tiptoes and see what happens. Alright Mara, go ahead and try, come on, what are you come on, let's go. What are you doing and HANDS stay behind the back! It doesn't work. Why not?

[Cut to Mara and Joanne sitting at the kitchen bar.]

Mara: So, um tiptoes against the wall doesn't work because you have to lean forward on your tiptoes but you can't lean forward into the wall.

Joanne: Exactly! So, in order stand on your tiptoes you have to lean forward a bit in order to keep your weight over your support. Try it at home you can't do it. There's one more thing you can try at home as well you can create all kinds of fun little bouncing sculptures or structures with everyday objects around the house. So Mara’s got a spoon and a fork here she's combining them together and then if we get the balance just right we can balance this structure on the glass with a match and Tadaa!

Mara: What happens if we light the match?

Joanne: Let's see! If you're gonna do this at home, make sure you get help.

[Joanne lights the match. They watch the match burn down together. The flame goes out as it approaches the edge of the glass.]

Mara: Wow it looks like magic it's like stable on pretty much nothing.

Joanne: Uh huh. It's better than magic. It's physics!

Mara: So, we could try some like rocks structures at the beach this summer.

Joanne: Yeah, that would be fun.

Mara: And you guys can try rock structures too!

[Rock images fade back to Mara and Joanne in the kitchen.]

Mara: Make sure to send us your videos on Facebook or Instagram and thanks for watching ask me anything science edition.

[Guelph Physics logo, sound.]

Dr. Joanne O'Meara and junior scientist Mara tackle the idea of stability, balance, and centre of mass!