Jason has created another robot. He wants to repeat the speed check, so he gathers data bout the robot's placement at different times. Based on the data provided, is the robot traveling at constant speed? Prove your answer.

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?