2. Distance difference ÷ speed difference = catch-up time;
3. Distance difference, catch-up time = speed difference.
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.
Extended data?
Solution to the problem: the conventional method is to list the equations according to the displacement equation, and the displacement formula of uniform linear motion is quadratic equation, so the quadratic trinomial (y=ax? +bx+c) (the properties and discriminant of △ = b? -4ac).
When two (or several) objects are moving, one of them is often taken as the reference object, even if it is "stationary", only the other (or several) objects are moving. This simplifies the research process, so the problem of traceability is often solved by changing the reference method. Before determining the motion of other objects, the initial velocity and acceleration of other objects relative to the reference object must be determined.
Reference source: Baidu Encyclopedia-Traceability Problem