# Two Cars (FUN PROBLEM)

1. Sep 2, 2009

### alexistheman

Two cars travel westward along a straight
highway, one at a constant velocity of
85 km/h, and the other at a constant velocity
of 107 km/h.

a) Assuming that both cars start at the
same point, how much sooner does the faster
car arrive at a destination 18 km away? An-
swer in units of h.
006 (part 2 of 2) 5.0 points

b) How far must the cars travel for the faster
car to arrive 18 min before the slower car?

So i think the answer for problem A) would be .02 h
but Im not Sure exactly if im doing this right.

2. Sep 2, 2009

### alexistheman

1.78km per min
18/1.78=10.11235955
1.41km per min
18/1.41=12.76595745
12.76595745-10.11235955=2.6535979

3. Sep 2, 2009

### alexistheman

I try to use my relative speed which is 22kph and my distance is 18km, using t = d/r i come up with .818182 but I dont understand how this applys.

4. Sep 2, 2009

### planck42

For your first problem, simply consider how long it takes each individual car to travel 18 km. The second will require a substitution.

5. Sep 2, 2009

### alexistheman

i came up with .04354h and it was right. lol.

6. Sep 2, 2009

### alexistheman

Now i need b)

7. Sep 3, 2009

### rl.bhat

Let x be the distance.
Find the time taken by two cars to cover that distance. The difference between the times should be 18 minutes.

8. Sep 3, 2009

### indep

lol..we must go to the same school..

9. Sep 3, 2009

### alexistheman

Lol indep, khs possibly?