Answer:
0.72 km per hour
Explanation:
First, find the speed in meters per hour. Create a proportion where x is this speed:
=
3x = 2160
x = 720
So, the speed is 720 meters per hour. Convert this to kilometers per hour by dividing 720 by 1000, since there are 1000 meters in a kilometer:
720/1000
= 0.72
So, the speed of the conveyer belt is 0.72 km per hour