Upcoming SlideShare
×

# Dave steam 2 (steam)(28)

466
-1

Published on

Part 2 - How steam 'works'

3 Likes
Statistics
Notes
• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

Views
Total Views
466
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
0
0
Likes
3
Embeds 0
No embeds

No notes for slide

### Dave steam 2 (steam)(28)

1. 1. Steam Engines<br />A series of lessons <br />by David C<br />Dec 2010<br />
2. 2. Part 2<br />Steam pressure<br />
3. 3. Okay people,<br />Now in order to understand how steam engines work, <br />I think it’s important to understand how steam itself works. <br />
4. 4. Okay people,<br />Now in order to understand how steam engines work, <br />I think it’s important to understand how steam itself works. <br />Here’s a cube of water, 1cm along each side, and I’m going to boil it. Of course, steam is going to come off. <br />
5. 5. Okay people,<br />Now in order to understand how steam engines work, <br />I think it’s important to understand how steam itself works. <br />Here’s a cube of water, 1cm along each side, and I’m going to boil it. Of course, steam is going to come off. <br />But what I really want to know is, how much space will that cubic centimetre of water take up when it turns into steam?<br />
6. 6. Here it is, here.<br />
7. 7. Here it is, here.<br />If allowed to expand to its natural size, steam will occupy 1600 times as much space as it did when it was water.<br />
8. 8. That means a cube 11 or 12 times as big along each side.<br />
9. 9. That means a cube 11 or 12 times as big along each side.<br />It’s a bit like saying that the water in your mouth, if boiled, would fill up the whole of your head.<br />
10. 10. Now if all that steam was confined inside a much smaller box, the molecules would be pressed up hard against the walls, desperately trying to get out. <br />
11. 11. Now if all that steam was confined inside a much smaller box, the molecules would be pressed up hard against the walls, desperately trying to get out. <br />… and that means we could get it to do things for us.<br />
12. 12. Here’s an idea that Isaac Newton came up with, in the 1680s.<br />
13. 13. Here’s an idea that Isaac Newton came up with, in the 1680s.<br />You boil some water and let the steam vent out through a backwards-pointing jet, and drive the cart forwards.<br />
14. 14. Here’s an idea that Isaac Newton came up with, in the 1680s.<br />How well do you think it would have worked?<br />