In this video, let's discuss about Spears, what is the spear?
This is an example of a spear.
It looks like a ball right now.
We need to know a few important things about the spear.
First, let's understand what is a total surface area of the spear that is this part over here.
Right.
But total surface area of a spear is given us for by our square.
All right.
So you need to remember this.
All right.
Now, what about the volume of the spear?
The volume of the spear is given us four by three by our cube.
So this is the volume of the spear.
Now, let's take the case of Amy Spear.
So this is an example of a spear right over here.
It has a circular base and this is half of it, but it's like cutting the spear into two.
All right.
Now, the cut to the surface area of the spear that is this part will be half of the total surface area
of the spear.
That is by our square by two.
Therefore, the current surface area over here is two by our square.
Now, what about the total surface area to the curved surface area?
You need to add the area of this circular base rate.
So that would be to Pyar Square.
This this one over here.
Plus Pyar Square.
Right.
That's true.
By our square, less by our square, which is equal to three by our square.
All right.
And what about the volume of the hemisphere?
That would be half the volume of the spill.
That's four by three by our tube.
By two, which is equal to two by three by our cube.
All right.
Now, we have seen the case of a spear and the case of the hemisphere.
Now, let's try to analyze the case of Sperry can sell.
All right, now, as medical shell will have some empty space inside it right now, if you have a spiritual
shell and you cut it and look at the cross section, it will look like this.
You will have a larger radius and a smaller radius.
Now, how would you find the volume of this particular shell?
That would be four by three by into our cube, minus our cube.
Why is that so?
Or that this is the same as four by three by our cube, minus four by three by our cube.
Right.
But what is it that we are doing?
If it was not a spiritual center, if it was a proper sphere, the volume would have been four by three
by a cube.
From that.
We are subtracting this part.
Right, which is hollow.
So that part has a volume of four by three by ArcView.
Where are is the smaller radius?
That's why the volume of this particular cell is given us or by three pi into our cube.
Minus are cube.
All right.
Now what is the total surface area?
You will have a surface area on the outside and on the inside this part.
Right.
So the total surface area will be the surface area over here that's on the outside, plus the same thing
on the inside.
So that's four pi into our square plus our square.
Remember, this is the same as or by our square, which is what you have on the outside plus or by our
square.
This is the surface area on the inside.
Now, these are the important formula and concepts that you need to know about the spear, mepa and
spherical.