Unit D Lesson D2
Completion requirements
Lesson D2: Simple Machines: Past and Future
Video Lesson
How have machines changed over time and how do humans invent new machines? Watch this video to learn more.
Lesson D2: Simple Machines: Past and Future
Figure D.1.2.1 β A pottery wheel helps shape round clay containers.
Figure D.1.2.2 β The spinning wheel was invented in the Middle Ages.
Figure D.1.2.3 β A spinning wheel twists wool fleece into knitting yarn.
Reading and Materials
for This Lesson
Science in Action 8
Reading: Page 269
Materials:
Plastic bottle cap, popsicle stick, tape, round pencil, mini marshmallow.
Art Wheels
Today, most dishes, yarn, and thread are made with large electric machines. Some people make clay pottery or spin yarn as artistic hobbies. Simple machines help artists create these handmade products.
Ancient people made clay pots, dishes, and jugs as food containers. Many clay dishes such as bowls and cups have a round shape. Ancient potters used pottery wheels to quickly form dishes in a perfectly round shape. They spun the pottery wheel by hand. Today, hobby pottery wheels are powered by electric motors.
Fibres like cotton and wool must be spun into thread before they can be woven into cloth. Ancient people used to spin thread directly onto a round spindle. In the Middle Ages, the invention of the spinning wheel made spinning thread faster and easier. A spinning wheel has a large wheel, a small wheel, and a foot pedal. Pumping the foot pedal makes wool spin around the wheels.
Today, most dishes, yarn, and thread are made with large electric machines. Some people make clay pottery or spin yarn as artistic hobbies. Simple machines help artists create these handmade products.
Ancient people made clay pots, dishes, and jugs as food containers. Many clay dishes such as bowls and cups have a round shape. Ancient potters used pottery wheels to quickly form dishes in a perfectly round shape. They spun the pottery wheel by hand. Today, hobby pottery wheels are powered by electric motors.
Fibres like cotton and wool must be spun into thread before they can be woven into cloth. Ancient people used to spin thread directly onto a round spindle. In the Middle Ages, the invention of the spinning wheel made spinning thread faster and easier. A spinning wheel has a large wheel, a small wheel, and a foot pedal. Pumping the foot pedal makes wool spin around the wheels.
Watch More
Spinning for Art
Watch this video to see how a spinning wheel works.
Watch this video to see how a spinning wheel works.
Modern pottery wheels are powered by an electric motor, but for many years, people turned pottery wheels by hand. This video shows pottery being made with a hand-turned wheel.
Figure D.1.2.4 β The Netherlands is a country with many windmills.
Figure D.1.2.5 β The inside of a windmill contains massive turning gears.
Figure D.1.2.6 β Modern windmills generate electricity.
Windmills
Windmills use wind energy to turn wheel and axle machines. Old windmills were often used to crush substances into fine powders. For example, windmills crushed grains into flour and rock minerals into paint pigments. The wheel and axle of the windmill sails connects to wheel and axle gears inside the windmill tower, which connect to a large grinding millstone.
The country of the Netherlands has many windmills. In the past, these windmills were connected to large Archimedes screws, which drained water out of the low lying farmland.
We no longer use windmills as grinding machines. However, modern windmills still use a wheel and axle to turn. Modern windmill blades connect to a turbine, which spins to create electricity.
Windmills use wind energy to turn wheel and axle machines. Old windmills were often used to crush substances into fine powders. For example, windmills crushed grains into flour and rock minerals into paint pigments. The wheel and axle of the windmill sails connects to wheel and axle gears inside the windmill tower, which connect to a large grinding millstone.
The country of the Netherlands has many windmills. In the past, these windmills were connected to large Archimedes screws, which drained water out of the low lying farmland.
We no longer use windmills as grinding machines. However, modern windmills still use a wheel and axle to turn. Modern windmill blades connect to a turbine, which spins to create electricity.
Watch More
The Power of Windmills
Watch this video to see how the inside of a windmill works to pump water.
Watch this video to see how the inside of a windmill works to pump water.
Figure D.1.2.7 β Moving water spins water wheels.
Figure D.1.2.8 β Water wheels transfer energy to other machinery.
Figure D.1.2.9 β A water frame could spin thread much faster than was previously possible. Image courtesy Ralph Malan.
Water Wheels
The force of flowing water turns water wheels. A spinning water wheel turns other machinery attached to the wheel.
Water wheels were originally used for lifting water. Eventually they were also put to work grinding substances like wheat and oats, similar to a windmill. In a sawmill, water wheels were connected to sharp saws that cut logs into lumber.
During the Industrial Revolution in the late 1700s, a man named Richard Arkwright invented a machine called a water frame. A water frame was connected to a water wheel, and spun thread much faster than a spinning wheel.
We no longer use water wheels to directly power manufacturing machines. Instead, we use massive water wheels inside hydroelectric dams. These water wheels are called turbines, and they are used to generate electricity.
The force of flowing water turns water wheels. A spinning water wheel turns other machinery attached to the wheel.
Water wheels were originally used for lifting water. Eventually they were also put to work grinding substances like wheat and oats, similar to a windmill. In a sawmill, water wheels were connected to sharp saws that cut logs into lumber.
During the Industrial Revolution in the late 1700s, a man named Richard Arkwright invented a machine called a water frame. A water frame was connected to a water wheel, and spun thread much faster than a spinning wheel.
We no longer use water wheels to directly power manufacturing machines. Instead, we use massive water wheels inside hydroelectric dams. These water wheels are called turbines, and they are used to generate electricity.
Watch More
The Power of Water Wheels
This video shows how a water wheel helps crush grain in a flour mill.
This video shows how a water wheel helps crush grain in a flour mill.
Watch this video to see a water wheel invention that cleans up trash in a harbour.
This video explains how large water wheels called turbines generate electricity.
Figure D.1.2.10 β A catapult is a lever that launches a heavy object into the air.
Figure D.1.2.11 β A trebuchet was a weapon used in the Middle Ages.
Catapults and Trebuchets
A catapult is a weapon that uses a lever. The catapult was invented in ancient Greece. At first, catapults were used to throw arrows longer distances. During medieval times, people invented better catapults to throw large rocks, flaming weapons, or dead animals into walled cities and castles. People stopped using catapults as war weapons after World War I, in the early 1900s.
The trebuchet is similar to a catapult. It was the most powerful war machine used in the Middle Ages. Trebuchets use a sling to extend their lever, which flings weapons at high speeds.
A catapult is a weapon that uses a lever. The catapult was invented in ancient Greece. At first, catapults were used to throw arrows longer distances. During medieval times, people invented better catapults to throw large rocks, flaming weapons, or dead animals into walled cities and castles. People stopped using catapults as war weapons after World War I, in the early 1900s.
The trebuchet is similar to a catapult. It was the most powerful war machine used in the Middle Ages. Trebuchets use a sling to extend their lever, which flings weapons at high speeds.
Watch More
Long Range Medieval Weapons: Catapults and Trebuchets
Watch this video to learn more about catapults and trebuchets.
Watch this video to learn more about catapults and trebuchets.
This video shows a trebuchet that throws flaming weapons.
Try It!
Marshmallow Catapult
Try this simple experiment to see how changing the fulcrum of a catapult affects the distance that an object can fly.
Materials:
Try this simple experiment to see how changing the fulcrum of a catapult affects the distance that an object can fly.
Materials:
- Plastic bottle cap
- Popsicle stick
- Tape
- Round pencil
- Mini marshmallow
Instructions:
- Tape the plastic bottle cap to one end of the popsicle stick with the open end of the bottle cap facing outward.
- Place a mini marshmallow in the plastic bottle cap.
- Use the pencil as a fulcrum. Lay the pencil down on a flat surface. Place the popsicle stick over the pencil, so they are perpendicular.
- Move the popsicle stick so the pencil fulcrum is located opposite to the bottle cap. The fulcrum should be one-quarter of the way along the popsicle stick, opposite to the bottle cap.
- It is now time to launch your marshmallow! Use your hand to strike down quickly on the end of the popsicle stick without the marshmallow. What do you observe?
- Move the popsicle stick so that the pencil fulcrum is halfway along the popsicle stick. Try launching the marshmallow again. What do you observe?
- Move the popsicle stick so that the pencil fulcrum is one-quarter of the way along the popsicle stick, but closer to the bottle cap side. Try launching the marshmallow again. What do you observe?
Questions:
Think about the following question very carefully. Then, type or write your answer. When you have your answer, click the question for feedback.
Think about the following question very carefully. Then, type or write your answer. When you have your answer, click the question for feedback.
The catapult with the fulcrum furthest away from the bottle cap made the marshmallow fly the longest distance. When a force was applied to the short end of the lever, the bottle cap end of the lever travelled a longer distance. This made the
marshmallow travel a longer distance at a faster speed.
Sharing:
Congratulations on building a marshmallow-launching catapult! Consider sharing your catapult (or any thoughts and experiences you might have regarding this activity) in the course Sharing Forum. Take a photo of it and post it. Your teacher and other students would be interested in seeing your catapult.
Congratulations on building a marshmallow-launching catapult! Consider sharing your catapult (or any thoughts and experiences you might have regarding this activity) in the course Sharing Forum. Take a photo of it and post it. Your teacher and other students would be interested in seeing your catapult.
Watch More
Force Advantage vs Speed Advantage
Watch this video to learn how the fulcrum position makes a lever have either a force advantage or a speed advantage. Did your best marshmallow catapult have a force advantage or a speed advantage?
Watch this video to learn how the fulcrum position makes a lever have either a force advantage or a speed advantage. Did your best marshmallow catapult have a force advantage or a speed advantage?
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit D Lesson 2 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps β if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
-
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Be a Self-Check
Superhero!
Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet β STOP β and go back to step 1 above. Do not look at the answers without first trying the questions.
Machines donβt always work the first time they are invented. If a newly invented machine fails, the inventor can observe what went wrong, refine and change the machine, and then try building it again. Making observations and changes is an experimental
trial and error process.
The first mixers were hand whisks. Whisks are a lever that people move by hand. Newer mixers were made from two whisks attached to wheel and axle gears. The gears and whisks were turned by a hand crank. Hand turning the crank on a mixer made
the whisks turn faster with less work. Modern electric mixers use electricity to turns a wheel and axle connected to the whisks, to make them spin at high speed. Electric mixers do not require any human work other than holding them.
Pennyfarthing bicycles were dangerous because their riders had to sit high above the ground. A chain and gear system on a bicycle made it possible to have equally sized smaller wheels, which made sitting on a bicycle much less dangerous.
Rowing paddles are levers. The rower moves the short end of the paddle a short distance, which makes the long end of the paddle move a longer distance. This propels the boat further and faster through the water.
A screwdriver tip can easily slip out of the slotted screw head. The square Robertson screw head prevents the screwdriver from slipping out of the screw, which means much more force can be applied to the screwdriver, and thus, the screw.