Solving Two-Object Motion Problems

[Illicitsky]

Homework Statement

1. Two people leave from two towns that are 195 miles apart at the same time and travel along the same road toward eah other. The first person drives 5 miles slower than the second person. If they meet in 3 hours, at what rate of speed did each travel?

Homework Equations

d= rt

The Attempt at a Solution

Simple motion problems are easy. But HOW do we figure out problems when two objects are going down the same road/path, with X miles in between or even 'overtake' the other?

No idea where to start. Tried to set up d=rt chart by there's too many variables in the problem (the 3 hours thing, then 5 miles slower?)

 

[ehild]

There are two towns, A and B, D distance apart. There are two people: the first starting from A with speed v_a, the other starts from B with speed v_b=v_a-3.

Denote the distance of the people from A by x_a and x_b. At the beginning, x_a=0, x_b=D

After t time elapsed, the first man is x_a=v_at distance from A. The other man is x_b=D-v_bt distance from A.

When they meet, they both are at the same distance from A: x_a=x_b.

ehild