Two people start at the same place and walk around a circular lake in opposite directions. one walks with an angular speed of 1.80 10-3 rad/s, while the other has an angular speed of 3.70 10-3 rad/s. how long will it be before they meet?

The angle that corresponds to a complete revolution around the lake is .

Taking the direction of the first person as positive direction, his angular position around the lake is

where  is the angular speed of the first person.

The second person is going in the opposite direction, so we can write his angular position around the lake as

where  is his angular speed, and  is the angle that corresponds to one complete revolution around the lake.

The two people meet when their angular position is the same:


from which we find the time t after which they meet again: