plain a is traveling at a speed of 500 mph plane b is traveling 45mph slower than plain a when will plain a and plain b pass each other

First let's assume that * d_{0}* miles is initial distance between two planes.

**1**. Both planes are traveling toward to each other with speed (500 + (500-45)) = 955 mph, and they will pass each other in (

*) hours.*

**d**_{0}/955**2.**Both planes are traveling in opposite directions with 955 mph and they will never "meet" each other.

**3.**Plane

*"tries to catch" plane*

**a***and it will happen in d*

**b**_{0}/(500-455) =

*hours.*

**d**_{0}/45**4.**Plane

*(slower moving one) "tries to catch" plane*

**b***.... and it will never happen.*

**a**
## Comments

You are considering only one-dimensional motion. In this case everything you have said is correct. But it is not reflected in the text of the problem. Yes, we can assume, that this is a one-dimensional motion. But my point is, the author who introduces the problem, has to be accurate in making statements, so we don't have to make any additional assumptions.