Okay, suppose the car is travelling with velocity , the tree has diameter and is at distance from the road; suppose the hidden person is hugging the tree, and that, looking down from above, the person, car and centre of the cross section of the tree trunk are always in a straight line.

Then I make it the speed of the person when the distance between the tree and the car is

is .]]>Given the following information:

You are in a car going 35 miles per hour. You pass a tree on the side of the road and there is a person behind the tree. You can never see who it is because they are always behind the tree.

How fast is the person going?

For an actual problem, one could estimate the distance to the tree from the car as being 24 feet and the distance from the tree to the person as being 6 feet. But those are only estimates.

Thanks.

]]>