37.8 seconds First, determine the speed difference between the car and truck. 95 km/h - 75 km/h = 20 km/h Convert that speed into m/s to make a more convenient unit of measure. 20 km/h * 1000 m/km / 3600 s/h = 5.556 m/s Now it's simply a matter of dividing the distance between the two vehicles and their relative speed. 210 m / 5.556 m/s = 37.8 s So it will take 37.8 seconds for the car to catch the truck that's 210 meters in front of the car.