Slow Sock on Lubricon VI

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Slow Sock on Lubricon VI : What would happen to a slowly moving frozen sock on a frictionless planet

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This is a picture of the planet : Lubricon VI
And Lubricon VI is a very special planet,
Because it's made of a yet to be discovered element called Lubrica
And Lubrica is special because if anything glides across the surface if Lubrica
It will experience absolutely no friction.
So if this right over here if a sheet of Lubrica
We're looking at it from the side.
And if we have a brick on top of it,
maybe gliding on top of it, like that,
it experiences absolutely, it experiences absolutely no friction.
Now the other things we know about Lubricon VI,
it's drifting in deep space,
and it does not have an atmosphere.
In fact, it is a complete vacuum outside
It's in such deep space,
such a remote part of space
that there aren't even a few hydrogen atoms.
right over here,
is a complete, absolute vacuum.
And it's also an ancient planet.
The star that it used to orbit around
has long since died away.
So it's just this lonely planet drifting in deep space,
without an atmosphere.
The other thing we know about Lubricon VI,
is that it is a perfect sphere.
it is a perfect sphere..
Now my question to you, for some bizarre reason,
There happens to be, on the surface of Lubricon VI,
so this right over here is the surface of Lubricon VI
There happens to be a sock that is frozen in a block of ice.
So this is my sock, and it's frozen
It's frozen in this block of ice.
And it happens to be travelling at 1 km/h.
in that direction.
If we look at it in that macro scale,
When we were looking at that planet,
Let's say that that is the frozen sock,
and it is traveling along the equator.
It is traveling along the equator of Lubricon, of Lubricon VI.
So my question to you, given all of these assumptions we made,
that it has absolutely no atmosphere
It's a perfect sphere,
and Lubrica has absolutely no friction
regardless of what's traveling on top of it.
What will happen to this rock,
or, or I should say..
to this frozen sock over time?
To answer that question, we need to
think about all of the forces
that are acting on this frozen block of
I guess, this frozen block of ice and sock.
And first of all, let's think about
the forces that are acting in the radial direction,
inward or outward of the center of the planet.
Well, this planet has a mass,
and so you have a inward force
towards the planet's center of mass.
And so you have the force of gravity acting on this block,
going radially inward to the center of the planet.
So I'll draw it like this,
So we have our force of gravity.
It's going radially inward, just like that.
But then we know that the block is
not just biraling towards the center of the earth,
We have the surface here.
It's not going to go through this surface of Lubrica.
We can also assume that Lubrica is a very, very. strong material.
So you also have a normal force
that is keeping the block from spiraling towards the center of the earth.
So this is a normal force.
And one thing I will think about now,
and will adress directly in another tutorial,
is whether this normal force is equal to the
is equal to the force of gravity.
We'll think about that in a future video.
But these are all the forces that are acting
in the radial direction.
either inward(towards the center of the planet)
or outward.
But if we think about the tangential direction,
along the surface of the planet,
there are no net forces.
And because there are no net forces,
in this tangential direction, right over here,
this block will not either accelerate, nor decelerate.
There is no air friction, there is no friction,
or I should say air resistance,
which is really the friction with the particles
if you had an atmosphere,
It's a complete vacuum, so there's nothing there.
There is no friction with the surface of the planet.
So there's no friction there,
which could have been a force in the tangential direction.
So there's absolutely no forces in the tangential direction.
So this block of ice will
actually continue to travel at 1km/h
for all of eternity.
So it'll just continue to do it
given the assumptions that we just made.