Math Is Fun Forum

Audra B.

Guest

Is there a way to solve this problem?

Is this a problem that can be solved?
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.

scientia

Member

Registered: 2009-11-13

Posts: 224

Re: Is there a way to solve this problem?

You also need to know the diamter of the tree trunk.

scientia

Member

Registered: 2009-11-13

Posts: 224

Re: Is there a way to solve this problem?

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

.

gk_2000

Member

Registered: 2013-03-02

Posts: 2

Re: Is there a way to solve this problem?

Ratio of the distance to tree from car and from person, is 24:6 or 4:1. So the person should maintain a speed of 35mph/4 ~= 9 mph