Two objects start from two places and walk in opposite directions. After some time, they are bound to meet on the road. This kind of problem is called meeting problem. The problem of meeting is to study the relationship between speed, time and distance. It is different from the general travel problem in that it is not the movement of an object, so the speed it studies includes the speed of two objects, that is, the sum of speeds.

Meeting distance = speed × meeting time

Meeting time = meeting distance/speed and

Speed Sum = Meeting Distance/Meeting Time

Meeting distance = distance traveled by A+distance traveled by B.

Speed of a = meeting distance/meeting time-speed of b.

Distance of a = distance of meeting-distance of b.

To solve this kind of problem, we should make clear the meaning of the problem, draw a line diagram according to the meaning of the problem, analyze the relationship between the quantities, and choose the solution method. In addition to finding out the distance, speed and meeting time, we should also pay attention to some important issues: whether to start at the same time, and if anyone in the topic starts first, we should remove the first distance and find out the distance to walk at the same time. Driving in the opposite direction, the same direction or the opposite direction. Different directions have different methods to solve problems. Whether to meet. Some topics are that moving objects do not meet, and the distance between them should be removed; Some problems are that both of them are missing, and the distance of multiple lines must be added up to get the distance of simultaneous driving.

Catch up with the problem

The chasing and meeting problems involved in the movement of two objects on the same straight line or closed figure are usually classified as chasing problems. This kind is often found in exams. Generally, it can be divided into two types: one is that two people chase and two people meet, which is relatively simple; One is that it is more difficult for many people to catch up and meet.

Catch-up distance = speed difference× catch-up time

Catch-up time = catch-up distance ÷ speed difference

Speed difference = catching distance ÷ catching time