Cactus Care

by Hannah | March 9, 2018
STEM Contest 2018

Recently for my 11th birthday, I got a beautiful little cactus. It needs just a misting of water every day. I kept forgetting to care for it, so I invented a Rube Goldberg Water Splash Machine. First I went downstairs and found a piece of edging that is made to attach the carpet to the edge of a step.Then I got two pieces of hollow plastic tubing, cut from the handles of the mop and the swifter sweeper. My mom will be surprised how short they are! Next, I attached the tubes and runway to a bowl of water on one side and a raised soda machine on the other, so that the marble and golf ball I planned to use would have a drop for momentum. I used some domino blocks to set off the marble at the top. It took a lot of tries before I got that just right so it would work.  Lastly, I attached two blocks to a shoestring and hung it from a cabinet door that my parents open every morning. The hanging blocks swing out and hit the dominoes that set off the marble. The marble travels down the pipes and goes down the metal slide where it hits the golf ball. It is stopped when it hits the golf ball by the tape that kept the golf ball waiting there.Now the golf ball is shot off down the slide until it splashes into the water, spraying a light mist onto my cactus. My job is done, my goal complete.

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