# How to Build a Miniature Scale of a Roller Coaster Out of Cardboard

Building a roller coaster out of corrugated card board is an appropriate science project for middle school and high school science and physics classes. These cardboard roller coasters test the designs of groups of students in the class to see which one keeps a tennis ball rolling all the way through the coaster. The lessons that accompany this project deal with velocity, kinetic potential, engineering and speed. Each student team must build a roller coaster that has three hills, and the tennis ball must start at the top of the first hill, go up and over the remaining two hills and come out the other side.

Draw your track design on the two pieces of corrugated cardboard. Measure 20 centimeters up from the bottom on the cardboard and draw a horizontal line across the bottom of the cardboard at this distance from the edge. Each valley of the roller coaster must touch the line and be 20 centimeters from the bottom edge. You can design the height of each hill in any configuration you want.

Cut out 25 4-by-12-centimeter rectangles and use these as spacers between the two tracks. Put glue along the 12-centimeter edges and press the rectangles into place between the two tracks. This will separate the two tracks by 4 centimeters and keep them stable and rigid while the tennis ball is on the track.

Cut out four more pieces of 4-by-12-centimeter cardboard rectangles. Cut two slits in the top of each rectangle to a depth of 2 centimeters and slide down the bottom of the track to stabilize it. Space the four rectangles equally across the bottom of the two tracks.

Add one or two large cardboard tubes along the track for added interest and to lengthen the track and vary the resistance. Attach one cardboard tube to the beginning of the track at the top and at the end of the track with a few drops of hot glue.

• Cut the two tracks exactly the same so your roller coaster runs smoothly and the tennis ball doesn’t fall off.
• Keep a bowl of cold water close by whenever you use a hot glue gun in case any glue drips on your fingers.

Patti Richards has been a writer since 1990. She writes children’s books and articles on parenting, women's health and education. Her credits include San Diego Family Magazine, Metro Parent Magazine, Boys' Quest Magazine and many others. Richards has a Bachelor of Science in English/secondary education from Welch College.