ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
Technology Videos 160 videos
What's the deal with wind? And why does it have to be so...windy?
How did people move stuff around before the wheel was invented? More importantly, why didn't they take a break for a few minutes from moving stuff...
History of Technology 1: Waterwheels 227 Views
Share It!
Description:
Waterwheels are crafty little thieves. Why? They stole a twenty out of our wallet once. Oh, and they also steal kinetic energy to do some useful things. Hit play to learn more.
Transcript
- 00:00
We speak student! water wheels are simple put a giant wheel in moving water and [a giant wheel in a lake]
- 00:08
the water makes the wheel turn boom end of video seriously what are you waiting
- 00:13
for roll that shmoop copyright screen alright fine it's a little more
- 00:16
complicated than that especially when we start analyzing energy flow water
- 00:21
flowing in a river has a whole bunch of kinetic energy thanks to gravity [a very small waterfall]
Full Transcript
- 00:24
dragging the water downhill toward the nearest ocean from a human perspective
- 00:29
all that energy is being wasted but water wheels are crafty little thieves [a waterwheel disguised as a thief in the fields]
- 00:33
they steal some of that wasted kinetic energy and make it do useful stuff like
- 00:39
grind grain saw timber or pump bellows all right why not sit back and let the [woman sitting by a pool with her feet in the water]
- 00:44
water do all those things can't earn your keep their water because of their
- 00:48
simplicity waterwheels haven't changed much since ancient times the water
- 00:53
wheels that crushed grain into flour two thousand years ago had the same basic [a modern day electrical turbine]
- 00:57
setup as the ginormous turbines producing electricity in China today hey
- 01:02
if ain't broke you know why fix it however thanks to several centuries of
- 01:07
tinkering water wheels have a definitely evolved us in a few ways well the goal [a building man tinkering with an electrical turbine]
- 01:11
was always to make them more efficient the first water wheels were horizontal
- 01:15
think of a normal water wheel lopped over on its side alright well this [waterwheel on its side in a small puddle of water]
- 01:21
is a video here just look at it instead well the axle stuck straight up out of
- 01:25
the water and into the floor of the mill where it turned on millstone there were [
- 01:30
no gears gadgets or doo-dads that's a shame as we love a good doo-dad [flying toy carrying a man away]
- 01:35
right well if we're comparing water wheel to cars the horizontal
- 01:38
waterwheel was the equivalent of the Model T got the job done but boy it [an olden car bobbing up and down as it drives down the road]
- 01:42
wasn't perfect at some point someone had the bright idea of standing a wheel
- 01:46
straight up on its edge these vertical wheels were called undershots because
- 01:51
all the water flows under them brilliant right well undershots were more [waterwheel with a pink line showing the undershots]
- 01:56
efficient than horizontal water wheels but technically they still only transferred
- 02:00
about twenty-five percent of the rivers energy to the mill that means [lots of water gushing down the river]
- 02:03
75 percent of the rivers energy was just wasting away down the river rivers man
- 02:08
such a freeloader well the main problem with undershot wheels was that they got in
- 02:12
their own way the river pushed the paddles forward but they lost speed [a wooden waterwheel in a small puddle of water]
- 02:16
dragging through the water and even more efficient version of the water wheel was
- 02:20
the overshot which was positioned so the water would run off of an edge and dump
- 02:26
itself all over the wheels paddles over shots are twice as efficient as under [an overshot waterwheel]
- 02:31
shot but for hundreds of years nobody knew which model was better because
- 02:34
people didn't understand the science of energy or have any way to measure it so
- 02:38
now let's imagine we're medieval Europeans who want to grind some weed [medieval people laying on a beach]
- 02:41
but we live on the coast not near a river what do we do what do we do curse our
- 02:46
parents and their beachbum way no well maybe if we get one more message from
- 02:50
them saying Prithee bring my board wax hither dude irritating messages aside [medieval boy stood on a beach with a blue phone]
- 02:56
we don't need to do that if we've got a tidal wheel well in coastal areas that
- 03:01
needed a water wheel ingenious folks built cause ways to trap the water that [a cause way of rocks used to trap water]
- 03:05
poured in at high tide after the tide receded they release the trapped water
- 03:10
through a narrow opening and use it to power a waterwheel which then allowed
- 03:14
those medieval beachbum parents more time to surf gnarlieth dude though if you [medieval parents surfing by the shore of the beach]
- 03:19
remember one thing from this video let it be this that evil beach bum parents
- 03:23
are the worst so get your own board wax [medieval parents standing on surfboards as the sun sets]
Related Videos
GED Social Studies 1.1 Civics and Government
When you're about to marry the love of your life, not many things could stop you. However, finding out that your future hubby is keeping his crazy...
Here at Shmoop, we work for kids, not just the bottom line. Founded by David Siminoff and his wife Ellen Siminoff, Shmoop was originally conceived...
ACT Math: Elementary Algebra Drill 4, Problem 5. What is the solution to the problem shown?