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The Slow Coaster

Boomerang  

Materials Used: 2x2 ft. peg board, rubber bands, ping pong ball, 1/4" wing nut, 1/4"x3" hex nut, carriage bolt, ruler. 

For this project, we were told to create a coaster using the materials given to us and make it as slow as possible. At the end of the creation period, we competed against the other groups to see whose coaster was the slowest. 

1. We started this process by brainstorming how we should create our coaster. 

2. We then decided to start by making it slope and go across the board in a zig zag fashion. 

3. Once we tried to roll the ball down, we had to make a couple of changes along the way to keep it rolling. We decided to make a little catch site at the first drop off to keep the ball from rolling off the side, which worked out great.

4. We then decided to make a speed bump step in between the two screws, in hopes that it would slow the ball down after it rolled down the steeper section. This did not work out too well as the ball seemed to bounce over this bump due to the rate it was traveling. 

Our strategies: 

  • We added in a speed bump to slow down the ball

  • We added in a side barrier on the first drop to save the ball from falling off the side. 

  • We twisted some rubber bands to slow down the speed of the ball.

  • We added in some double rubber bands (two next to each other) to make sure the ball stayed on the path and did not fall through. 

  • We made some areas where the ball dropped through the rubber bands at the end of the line onto the line below. We did this in hopes that it would slow the ball down some as it slowly fell through the band. 

5. We continued the zig zag lines for the rest of the way down our board.​

6. We would have continued this pattern all the way down if we had more time. 

  • The rubber bands were used to tie around the screws in order to create a path for the ball to travel. 

  • The screws fit into the holes of the peg board, using the hex nut to stop the screw at the length you want, creating different lengths to guide our ball down the path. 

  • Lastly, the wing nut was twisted onto the back to hold the screw in place, as shown above.  

The Science Behind Our Coaster: 

  • Due to the force of inertia, objects will continue to remain unchanged and travel in a straight line, as shown by the ball traveling down the path at a constant speed. However, once an unbalanced force acts upon an object, it changes movement. In this situation, we see the ball rolling down the path and then changing direction as it falls down to the next row. This is due to the force, gravity, pulling downward on the ball as the rubber band is pushing up at the same time, keeping the ball balanced. However, when the rubber band runs out, there is nothing pushing up against gravity, creating an unbalanced force, causing the ball to drop to the next row. The last force that is seen here is friction. Friction is an unbalanced force that causes an object to slow down or when it is very strong, to stop altogether. In this situation, friction occurs between the rubber band and the ball as it travels down the path. The knots in the coaster(speed bump), as well as the twisted rubber bands, also act as friction causing the ball to hit it and slow down. Lastly, friction and gravity work against each other as gravity is pulling the ball down the path, while friction is trying to slow it down. As the ball gains speed, this means that gravity is winning the race against friction. Below are a couple images that help better explain the forces of science in this project! 

The average speed of our coaster:

about 20.19cm/sec. 

distance=38+9+4.5+5+38+11+38+4+19+13+3= 182.5cm 

seconds it took for our run: 9.04 sec

​

cm/sec: 182.5cm/9.04 sec=20.1880531

Connection to the K-6 Science Curriculum: â€‹

      1. Kindergarten 

K.P.1: Understand the positions and motions of objects and organisms observed in the environment.

     K.P.1.2: Give examples of different ways objects and organisms move (to include falling to the ground when dropped): -Straight -zigzag -round and round -back and forth -fast and slow. 

      2. First Grade

1.P.1: Understand how forces (pushes or pulls) affect the motion of an object.

      1.P .1.3: Predict the effect of a given force on the motion of an object, including balanced forces.​

     3. Third Grade

3.P.1: Understand motion and factors that affect motion.

     3.P .1.1: Infer changes in speed or direction resulting from forces acting on an object.

     3.P .1.3: Explain the effects of earth’s gravity on the motion of any object on or near the earth.

3.P.3: Recognize how energy can be transferred from one object to another.

      3.P .3: Recognize that energy can be transferred from one object to another by rubbing them against each other.​

     4. Fifth Grade

5.P.1: Understand force, motion and the relationship between them.

     5.P .1.1: Explain how factors such as gravity, friction, and change in mass affect the motion of objects.

     5.P .1.2: Infer the motion of objects in terms of how far they travel in a certain amount of time and the direction in which they travel.​

Our Slow Coaster in Action 

Math Tools Used: 
This project incorporated many math skills such as: 
  • multiplication, division, addition, subtraction  
  •  rounding 
  • slope
  • units of measurement 
  • measuring 
  • calculating speed: distance/time 

© 2017 created by Madison Sivret

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