Carpool, or Pool Car?

Carpool, or Pool Car?

November 4, 2019

Pools and bathtubs are a great place to play and to relax. But have you ever gone swimming in one while it’s rolling down the road? Duncan Forster and Phil Weicker tried it: they turned an old car into a hot tub. They took apart a 1969 Cadillac, added steel bars across the bottom to hold all the extra water weight, and then built a hot tub that fit perfectly inside the car. They filled it with water, and as you see here, they can drive it like that! They’ve nicknamed the car “Carpool Deville” and hope to set the world land speed record for the fastest-moving tub, because believe it or not, no one has tried this stunt yet.

Wee ones: If your car had a tub in it, how many tubs would your home and car have together?

Little kids: If you’re adding 400 gallons of water to the pool car, how would you count that up by 100s?  Bonus: If the car holds 2 people and 7 more rubber duckies than people, how many riders are there?

Big kids: If the highway speed limit is 60 miles per hour and the guys drive their tub just 1 mile per hour more slowly than that, how fast a record do they set?  Bonus: The two men raised $10,000 for their project, and bought the old car for $800 on eBay. How much money did that leave them to rebuild the car? (Hint if needed: What would they have left if they’d bought the car for $1,000?)




Wee ones: Different for everyone…figure out how many tubs you have in your house, and add 1!

Little kids: 100, 200, 300, 400.  Bonus: 11 riders, since there are 9 (7+2) rubber duckies.

Big kids: 59 miles per hour.  Bonus: $9,200.

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About the Author

Laura Overdeck

Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.

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