A car leaves Denver at 30 km/h traveling south. Two hours later, another car leaves Denver traveling south at 40 km/ h. How many hours had the first car been traveling when the second car catches up?

Please help I am lost on this one and another one i posted

this is another just like the others.

The relative speed of the 2nd car is 10 km/hr faster.

In two hours, the 1st car has gone 60km.

So, it takes 6 hrs for the 2nd car to catch up. By that time, the 1st car has been going for 8 hours.

Or, as Reiny showed you, you want to find where the distances are equal. Since distance = speed * time,

30x = 40(x-2)
30x = 40x - 80
10x = 80
x = 8

mofor left home and drove south at an average speed of 21mph. emily left 2 hours later and drove in the same direction but with an average speed of 35mph. find the numbr of hours mofor drove before emily caught up.

To find out how many hours the first car had been traveling when the second car catches up, we need to determine the time it takes for the second car to catch up to the first car.

Let's break down the problem step by step:

1. Calculate the head start of the first car: The first car leaves Denver two hours before the second car, so it has a head start of 2 hours. We will calculate this head start in terms of distance.

Distance = Speed * Time
Distance = 30 km/h * 2 h = 60 km

2. Determine the relative speed: To find out how long it takes for the second car to catch up, we need to calculate the relative speed between the two cars. The relative speed is the difference in their speeds.

Relative Speed = Speed of the second car - Speed of the first car
Relative Speed = 40 km/h - 30 km/h = 10 km/h

3. Calculate the time taken for the second car to catch up: Now we can calculate the time taken for the second car to cover the initial head start distance of 60 km at a relative speed of 10 km/h.

Time taken = Distance / Relative Speed
Time taken = 60 km / 10 km/h = 6 hours

Therefore, the first car had been traveling for 2 + 6 = 8 hours when the second car catches up.