# Distance and speed

1. Mar 6, 2014

### nowayn

1. The problem statement, all variables and given/known data
two people walk at a straight line towards each other at 4m/s from a starting distance of 500m.
a bee is flying between them at 10m/s and when its reaches the other person walking it turns around and fly's the other way and keeps doing so until the two persons walk into each other.
How many times can the bee fly between them before the two people walk into eachother

3. The attempt at a solution
i have a good understanding of math and physics, and i have tried to do a formula but i just can't get it to work.
if posted wrong let me know.
edit: starting to think that its probably a paradox because eventually there is 1m and the bee turns around and fly the other way and then its 0,6m then 0,3 then 0,1 etc.

Last edited: Mar 6, 2014
2. Mar 6, 2014

### HallsofIvy

The two people are walking toward each other (not "against each other"- that's your English lesson for today!) at 4 m/s. When you say "at 4m/s" I assume you mean each is walking at 4 m/s relative to the ground so closing on each other at 8 m/s. It will take them $500/8= 62.5$ seconds to meet. The bee is flying at 10 m/s. How far will it fly in 62.5 seconds?

3. Mar 6, 2014

### voko

How long will the people walk till they meet?

4. Mar 6, 2014

### nowayn

ooh sorry for bad explication. the be fly's to one of the people walking then turns around and fly's to the other one and keep doing so until they meet. But i have come to realize that its probably a paradox because eventually there is 1m and the bee turns around and fly the other way and then its 0,6m then 0,3 then 0,1 etc.

5. Mar 6, 2014

### voko

#2 contains an almost complete solution. Think it over.

6. Mar 6, 2014

### nowayn

both of you misunderstood the question i think. the be fly's to one of the person then fly's back to the original person then flies to the other person again and keeps doing so until they walk into each other. how many times will the be fly back and forth before they walk into each other.

#2 ask's how long will the be fly in 62,5s. which is 625m. but thats not the question. the question is how many times will the be fly back and forth

Last edited: Mar 6, 2014
7. Mar 6, 2014

### voko

That question makes no sense unless you define how big the bee is. If it is just a point, it will fly back and forth infinitely many times.

8. Mar 6, 2014

### nowayn

yeah after some thinking, that started to be my main theory. the question came from my physics teacher who said that it would be on the test tomorrow so maybe he left out some part or its a trick question. nice to have some backup on my theory tough.

9. Mar 7, 2014

Why is that?When two person meet,the bee would stop flying.

10. Mar 7, 2014

### voko

The bee is faster than the two persons combined. So when there is some small distance left between the persons, the bee will cross it faster than the two persons, which will leave some still smaller distance, and the whole thing will repeat.