Joe’s Tree House Project
Systems and Simple Machines Supplemental Booklet The Monroe 2–Orleans BOCES Elementary Science Program encourages students and teachers to visit: www.espsciencetime.org
…a resource for students and teachers of elementary science. You’ll find information about: ESP Kits and Services Podcasts featured animal sites Measuring Challenges Summer Institute Newly Released Units Monthly Activities The Science Times Newsletter StreamingVideoSupport Upcoming Workshops safety tips and more! 2 Table of Contents
Chapter One - The Idea ...... 4
Chapter Two - The Question ...... 5
Chapter Three - The Lever ...... 7
Chapter Four - The Wheel and Axle . . . . . 9
Chapter Five - The Pulley ...... 11
Chapter Six - The Inclined Plane ...... 14
Chapter Seven - The Wedge ...... 16
Chapter Eight - The Screw ...... 19
Chapter Nine - Making it Our Own ...... 21
3 The Idea Chapter One
It was Saturday afternoon . Joe and Jake were spending the day playing in Jake’s tree house . Jake’s father built the tree house . The boys loved playing in it . It is a place they can let their imaginations run wild . The two boys were playing with the toys and games Joe had brought over in his wagon . The day went by very fast . It was 5:00 p .m ., and Joe had to go home for dinner .
“Well, Jake, I should be going . My mom told me to be home by 5:00,” said Joe .
“OK,” said Jake . “Tomorrow we leave for our spring vacation . We’ll be back in a week . I’ll see you then .”
“See you then,” said Joe . “Have a great time on vacation!”
“Thanks,” said Jake .
Joe put his toys back into his wagon and walked home . On his way home, he thought about how much fun he had playing with his friend in the tree house . Joe began to think about his own backyard . There is a tree in the back, left corner of his yard . It is an old tree, but its branches are strong . He remembered climbing the tree with Jake one afternoon . He wondered if that tree would be a good place to build a tree house of his own . He decided he would ask his dad at dinner .
4 Chapter Two The Question
Finally, it was dinner time . Joe was very hungry from playing all day, but he was also wondering what his dad would say about building a tree house . After everyone at the table passed around the plates of food, Joe knew that this was the time to ask his dad about having a tree house in his backyard .
“Dad,” Joe said . “I played at Jake’s house today . We played in his tree house all afternoon .”
“That’s great, son,” said Joe’s dad . “Bet you are hungry for dinner .”
“Yes, I am,” said Joe . “Dad, what do you think about the big tree in the back corner of our yard? I was thinking it would be a perfect place to build a tree house .”
“Which tree are you talking about?” asked Mr . Jemison .
“The old tree that I sometimes climb with Jake . It’s very strong,” said Joe .
“That is a strong tree, but it needs some work,” said Joe’s dad .
“I could help you fix it up,” said Joe . “I would want to help .”
Joe’s parents looked at each other . They knew how much Joe loved playing in Jake’s tree house . Joe and Jake had spent hours in it . Joe’s parents thought that if there was a tree house in their yard, then Joe could invite all his friends over to play in it .
5 “Well, Joe, I’ll make a deal with you,” said his father . “We will work on building the tree house, but you have to help me along the way .”
Joe’s face lit up . He couldn’t believe his parents said yes!
“I will help! I promise!” said Joe .
“We can start on the tree house tomorrow,” said Joe’s dad . “Tonight, we will need to get a plan together .”
Joe agreed . That night Joe and his dad made a plan for the tree house . Joe’s dad drew out the plans . The plan helped them see how much wood they would need . They also made a list of the tools they would need to build it .
6 Chapter Three The Lever
The next day Joe and his dad went out to the tree in their backyard . They wanted to take a close look at it . The tree would have to be a strong tree to hold the heavy tree house .
“So, what do you think, Dad? Do you think we could build a tree house in this old tree?” asked Joe .
“It looks pretty good,” said Joe’s dad . “We will have to take these nails out of the tree first .”
“Why are the nails in the tree?” asked Joe .
“I’m not sure,” said Mr . Jemison . “This is an old tree . These nails could have been there from a long time ago . Maybe someone hung signs on the tree . I think the nails will get in the way of our tree house . We need to remove them .
Joe’s father went to the garage to get his hammer . Joe thought his dad was going to hammer the nails into the tree . Instead, he used the claw end of the hammer . He started by making sure one of the nails was in the claw of the hammer . He held the top of the hammer against the tree . Then he pulled down on the hammer’s handle . The nail slid out of the tree . Joe watched as his dad pulled out all the nails .
“Dad,” said Joe . “I think you are using the hammer as a lever .”
7 Joe’s dad smiled . “Really? Can you explain what you mean?”
Joe explained, “The top part of the hammer that is on the tree is the fulcrum . The nail you are pulling out of the tree is the load . You are pushing down on the handle of the hammer . That is the force . It pulls the nail out of the tree .”
“Are you studying about simple machines in school?” asked Joe’s dad .
“Yes, we are . We learned that simple load machines are all around us . I think I’m pretty good at force finding them,” said fulcrum Joe .
“Well, you let me know when you see a simple machine,” said Joe’s dad . “I’d like to learn more about them, too .”
“Sure, Dad . No problem,” said Joe .
Joe and his dad could not work on their tree house for long today . Joe had a baseball game to play . They did get all the old nails out of the tree . The tree was ready for the next step .
8 Chapter Four The Wheel and Axle
The next day, Joe and his dad went to the lumber store . They bought all the wood they would need to build the tree house .
“That is a lot of wood,” said Joe .
“Yes, it is,” Joe’s dad agreed . “It is good we made a plan last night so we knew how much to buy .”
After Joe’s dad paid for the wood, a few men from the store helped them carry the wood out to their car . Joe noticed some of the men carried the wood by hand . Others used a cart to carry out the wood . The cart helped them carry a lot of wood at one time . Joe also noticed that the cart moved on wheels and axles . He knew that a wheel and axle is another simple machine .
As he watched the men put the wood in the truck, he looked around and saw there were wheels and axles everywhere . Their car had wheels and axles . The lumber store’s delivery trucks had wheels and axles . The carts that the customers were using to bring the things they bought to their cars had wheels and axles .
Mr . Jemison thanked the men at the lumber store for their help . When they got back into the car, Joe told his dad about his discovery .
“Dad, I found more!” Joe yelled .
“More what?” asked his dad .
“I found more simple machines . There are wheels and axles everywhere!” exclaimed Joe . 9 Joe’s dad chuckled . “Oh, more simple machines . Well, tell me where you see the wheels and axles,” said his dad .
“There are wheels and axles on the cart we used to carry out the wood . There are wheels and axles on the carts customers use in the lumber store . The delivery trucks have wheels and axles on them . Even our car has wheels and axles on it!” said Joe excitedly .
“Yes, I see what you mean . I can show you another wheel and axle, too,” said Joe’s dad .
Joe wondered what wheel and axle he had missed .
Mr . Jemison explained that wheel the steering wheel of the car was also a wheel and axle . axle “Look at the steering wheel of the car . The wheel we use to steer the car is connected to an axle that is attached to the car . It is this wheel and axle that turns the wheels of the car .”
Joe smiled . He couldn’t wait to tell his teacher what he had learned .
After they got home from the lumber store, they unloaded all the wood out of the truck . Joe was glad that he and his dad had everything they needed to start the tree house . They would begin to build it tomorrow after his dad got home from work . Joe wanted to get it finished before Jake came back from vacation . But after looking at the pile of wood, Joe began to wonder, how were they ever going to get all that heavy wood up into the tree? 10 Chapter Five The Pulley
The next day, Joe and his dad were ready to start building the floor of the tree house . They began by cementing a post into the ground that would hold one side of the tree house . The other side of the tree house would be held up by the tree itself . Joe’s dad used very large bolts and screws to attach wood beams to the tree and the post . These wood beams would make up the frame for the tree house floor .
Since it was just Joe and his father building the tree house, his dad was a little worried about how they would get the heavy lumber for the floor up into the tree . They had a ladder that Joe’s dad could use to lift the heavy boards, but that would be very hard to do . So he had to think of another way to lift the boards up into the tree .
Just then, Mr . Jemison saw something in his toolbox . It was an old pulley he had used years ago . He wondered if he could use the pulley and a rope to lift the heavy wood beams . He thought it was worth a try . So he set up a fixed pulley by attaching the pulley to one of the wood beams already in the tree . Then he threaded the rope through the groove in the wheel . One end of the rope was tied to a piece of lumber . The other end of the rope was hanging from the pulley . He knew Joe could pull on that rope to lift the heavy wood boards to him up in the tree .
Joe ran to the backyard to help his dad . He saw the pulley system his dad had set-up .
“Dad, that’s a pulley system!” exclaimed Joe . 11 “I thought you’d recognize it,” said Joe’s dad .
“Why are we using a fixed pulley?” Joe asked .
“Well, since it is just you and I lifting the boards up into the tree, I thought we could use a little help . If you pull down on the free end of the rope, that should lift the wood boards into the tree . I will climb up into the tree with the ladder . I will be there to grab the wood when it reaches the floor boards .
They gave the pulley system a try . They wrapped one end of the rope around the wood boards, and Joe pulled down on the other end of the rope . His dad grabbed the wood as it was lifted and untied the rope from the wood . Then he attached the wood boards to the floor beams . They did this over and over again until the floor of the tree house was complete . “Dad, that was easy!” said Joe .
“It was easy . That pulley was a good find,” said his dad .
“The fixed pulley system you put together let me pull down on the rope with the force of gravity . Then the wood boards rose up . It’s always easier to pull with the force of gravity than against it,” said Joe .
“We could have put together a movable pulley system .
12 That would have made lifting the wood boards into the tree even easier . Do you know about that pulley system?” asked Joe’s dad .
“Yes, I do . We would have to tie the rope to one of the wood beams already up in the tree . Then the pulley would be attached to the pieces of wood we were moving . But, Dad, I just thought of something . You would have needed to pull up on the other end of the rope,” said Joe .
“Yes, that’s true,” Joe’s dad agreed .
“But wouldn’t pulling up on the rope be harder than pulling down with the force of gravity?” asked Joe .
“WhenWhen you are pulling down with the force of gravity, it does feel easier . However,However, you are still pulling the full load . With With the movable pulley, you are pulling against the force of gravity, but one end of the rope is attached to the wood beam . ThatThat woodwood beambeam isis supporting half of the load . SoSo itit feels like you are lifting only half the load,” explained Mr . Jemison .
“Oooohhhhhh,” said Joe . “I get it .”
Joeoe and his dad finished the floor of the tree house that day .They They were were ready to put up the walls and add the roof to the tree house . But they would save that task for another night . It was time to go inside and get ready for dinner .
13 The Inclined Plane Chapter Six
The next challenge for Joe and his dad was to build the walls and roof of the tree house .
Building the framework for the walls and roof of the tree house was the easy part . Joe and his father used their pulley system to, once again, raise the frames for the walls and roof up into the tree . Joe’s dad attached the frames for the walls to the floor of the tree house and to each other . After the framework for the walls was finished, they were ready to finish the roof .
Joe and his dad went to a home improvement store to look for large pieces of metal that they could use for the roof . Once again, they found what they were looking for . They brought these large metal pieces out to their car using the carts with the wheels and axles that Joe had noticed before . Then they headed back to their house .
When they got home, Joe’s dad started to think about how they were going to get these large pieces of metal up into the tree house . Their pulley system would not work as well this time because the pieces of metal were very wide . It would be hard to wrap the rope around it .
“Well, Joe, I guess I’m going to have to carry these metal pieces up into the tree by using the ladder,” said his father .
Joe had an idea .
“Dad, I know about a different simple machine that could help us,” said Joe .
“What’s that?” asked Joe’s dad . 14 “Well, you know that large piece of wood that you have stored in the garage?” asked Joe .
“Yes,” said his dad .
“Why don’t we use the wood to make a ramp or inclined plane? One end of the wood could lean on the floor of the tree house . The other end would be on the ground . Then we could put a piece of metal on it and push it up the inclined plane . You could grab it when it reaches the floor of the tree house . It would be easier moving the metal that way then by lifting it straight up and climbing up the ladder with it,” explained Joe .
“That would be easier,” said his dad . “By going up the ladder, we are lifting the load straight up against gravity . Using an inclined plane would allow us to use less force to move the metal . I like that idea, Joe . Let’s try it,” he said .
Joe and his dad set up the inclined plane and moved the pieces of metal to the floor of the tree house . Then Joe’s dad lifted the metal pieces onto the roof . Once on the roof, the metal pieces were attached to the wood frame .
All that was left to do was finish the walls of the tree house . Joe and his dad had come a long way in building this tree house . Joe could not believe they were close to being finished . He could not wait to show his friend, Jake . Jake was coming back from vacation in a few days . He wanted to show him all the work he and his dad had done .
15 The Wedge Chapter Seven
Joe and his dad began to work on putting up the walls of their tree house . Joe’s father carried a saw and some of the wood into the backyard .
“Joe, we are going to have to do some good measuring today . We will measure the pieces of lumber we need for the walls of the tree house . The wood pieces we have are too long . We will need to cut them to the correct length,” explained Joe’s dad .
“OK, Dad . I can help you . I’m a pro at measuring,” said Joe .
“Good,” said Mr . Jemison .
Joe and his dad climbed up to the tree house using the ladder . Joe’s father reminded him to be very careful while using the ladder . He did not want Joe to fall .
“OK, let’s start . Joe, take the end of my tape measure and place it on the floor of the tree house,” Joe’s dad said .
As Joe held the end of the measuring tape, his dad stretched the tape upward to the roof of the tree house . Then he read the correct measurement .
“It is 62 inches,” said his father .
“Now move to the other corner of the tree house,” Joe’s dad instructed .
Joe held the end of the measuring tape until his dad got all the measurements 16 he needed . Carefully, they made their way down from the tree house .
First, Joe helped his dad measure the pieces of wood and mark where they needed to be cut . Then his dad put on his safety goggles, grabbed the saw and began cutting .
“Joe, the saw is very dangerous . I want you to stand back as I cut the wood to the length we need .”
As Joe looked at the saw, he could see its sharp edge . He remembered learning about a simple machine called a wedge . A wedge has a thin edge that is used to split or cut objects . As he watched his dad cut the first piece of wood, he was sure that the saw was a wedge . It was another simple machine that he had found .
“Dad!” yelled Joe . “The saw is a wedge! The saw is a wedge!”
“What?” his dad asked .
“I found another simple machine . The saw is a wedge . We are using it to cut through the wood . That’s what wedges do . They split or cut things . A knife is a wedge, an axe is a wedge, and a saw is a wedge!” exclaimed Joe .
“And the nails we are using to hold the pieces of wood together are wedges, too,” his dad said . “When I hammer the nails into the wood, the nails split the wood as they move through it .”
17 Joe’s dad finished cutting the wood to the lengths he needed for one of the walls . His dad nailed the pieces of wood to the frame of the tree house . They did this for all four sides . Now the tree house was completely closed in . His dad used a different kind of saw to cut out windows in the walls of the tree house . Then they added some wood boards to the walls on the inside of the house . It was starting to feel like a real house!
They needed to add one more thing to the front of the tree house . This very special tree house needed a front door .
18 Chapter Eight The Screw
Joe thought that he and his dad would need to go to the lumber store again . Joe didn’t know that his dad had already ordered a special door for the front of his tree house . That morning, Joe’s father brought out the door as a surprise for Joe .
“Wow!” said Joe . “What is that?”
“It’s the door for your tree house . I ordered it, and I made sure it was your favorite color, blue,” said Joe’s dad .
“Thanks, Dad!” said Joe . “It’s perfect!”
Mr . Jemison unwrapped the door . He gave Joe all the pieces they needed to attach the door to the tree house . Joe took a close look at the hinge and the screws needed to attach the hinge to the tree house . He remembered learning in class that a screw is a simple machine . He wanted to be sure he told his father about it .
“OK, Dad,” said Joe . “I have one more simple machine to tell you about .”
“What’s that?” asked his dad .
“I don’t know if you know this, but a screw is a simple machine,” said Joe .
“Can you tell me about it?” asked his dad .
19 “A screw is actually an inclined plane wrapped around a metal rod,” explained Joe . “See the threads around this screw? The threads are the inclined plane . The threads help keep things fastened together .”
“Sounds like those screws are going to be a big help to us . We are using them to attach the door to the tree house . We certainly don’t want it falling off its hinges!” said Joe’s dad .
Joe smiled at his dad . Then he began to look around . His tree house was almost done! He couldn’t believe it . He and his dad worked so hard to get finished . Jake was coming over to his house in a few days . He could hardly wait to show him all they had done .
20 Chapter Nine Making it Our Own
Today was the day! Jake was home from vacation, and Joe invited him over to his house . He was excited to show him his new tree house . He knew Jake would love it . They would have a whole new place to play with all their fun toys and games . He heard his mom call his name and say that Jake was at the door . He ran out of his room to greet Jake .
“Jake, I have to show you something!” yelled Joe .
Jake was surprised that Joe was so excited .
“What’s going on, Joe?” asked Jake .
“You’ll see,” said Joe .
Just then he opened his back door . He pointed to the large tree in the far corner of his yard . Jake’s eyes opened wide .
“So, what do you think?” asked Joe .
“Is that what I think it is?” asked Jake .
“It sure is,” said Joe . “Want to climb up?”
“Let’s go!” yelled Jake .
21 Joe and Jake ran to the backyard . Joe and his dad had added a ladder to climb up into the tree house . The boys climbed up the ladder to check out this new place .
“Wow, Joe . You and your dad did a lot of work!” said Jake .
“Yeah, we worked hard . But it was all worth it . Now we have a new place to hang out and play . Will you help me set it up?” asked Joe .
“Sure,” said Jake . “What do you need?”
“I’m not sure,” said Joe . “I just want to make the tree house fun . We’ll have to think about what we want up here .”
“Oh, I have some great ideas!” said Jake .
“OK,” said Joe . Let’s make a plan!
22 23 Written under funding from Monroe 2–Orleans BOCES December 2011 by Antoinetta Quinn.
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