Help with a Physics Question: One-Dimension Kinematics?

Question

I'm having a little trouble doing this. "A car traveling 95 km/h is 350 m behind a truck traveling 75 km/h. How long will it take the car to reach the truck?"

Answer 1

First of all, you need to choose which viewpoint you are going to go with. I would suggest the lorry driver.

We can say that the car driver is driving at 20 km/hr relative to him (he is travelling at 75 km/hr and the car driver is going at 20 kn/hr faster than him)

The car is 350m behind. Assuming the car is moving at 20 km/hr, then it would take 63 seconds to close in on the lorry

350m =0.350km

0.350/20 = 0.0175 hours to cover the distance

0.0175*60=1.05 minutes

1.05*60= 63 seconds

Hope this helps