### Home > INT2 > Chapter 5 > Lesson 5.2.5 > Problem5-121

5-121.

In order to quickly get people between terminals in the Minneapolis Airport, long “people mover” conveyor belts were installed. Assume that if someone stands still on a conveyor belt, that person will travel $2$ feet per second.

1. Since Jung is in a hurry, he decides to walk on the conveyor belt (in the same direction he wants to travel). If his terminal is $300$ feet away and he wants to get there in $60$ seconds, how fast does he need to walk? (Assume he can ride the conveyor belt the entire distance.)

If Jung just stood on the conveyor belt, how far would he travel in $60$ seconds?
How much farther would he need to travel?

Jung would travel $(2)(60)$ or $120$ feet if he just stood on the belt.

Jung would need to make up a distance of $180$ feet in $60$ seconds by walking.

$3$ feet per second

2. Jacob, who is four years old, decides to walk on the conveyor belt in the “wrong” direction (that is, in the direction opposite to which he would travel if standing still). If he walks for $18$ seconds at a rate of $1$ foot per second, how far will he travel? In what direction does he travel? Explain.

Jacob is walking backwards at a rate of $1$ foot per second, but the belt is moving him forwards at a rate of $2$ feet per second.