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Q & A: Dogs in Trucks

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Most recent answer: 10/22/2007
My question is why did my dog fall out of my Dads truck when he went around a corner really fast?
- Billy (age 7)
Decatur, Illinios
Dear Billy,

Your unfortunate dog has discovered (the hard way) something that Isaac Newton wrote down a few hundred years ago in his "First Law", which says that something moving will keep moving in a straight line at a constant speed unless some force pushes on it.

As your truck drove along the road (with your doggie in the back) your dog was moving just like the truck. When your dad turned the steering wheel, there was a force between the road and the wheels on your truck that made the truck turn the corner. In order for the dog to turn the corner also, there needed to be a force acting on him. (This is the same force you feel when you sit in the truck as it turns...the seat pushes at you in the same direction that the truck turns.) If the back of the truck is slippery, then there won’t be enough force on the dog to make him turn the corner, and he will fall off.

You will experience the same thing if you are sitting inside the truck and the seat is slippery. If your dad turns to the left, you will feel like sliding toward the right side of the seat. Really, this is just your body trying to keep going in a straight line as your truck it turning left underneath it.


(published on 10/22/2007)

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