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You are driving at 35 m/s east and notice another car that is initially located 462 m in front of you and is moving east at 25 m/s. How far do you travel before you pass the other car?

Respuesta :

The easiest way to answer this question is by realizing there are relating the velocities of the two cars. To tackle this problem, you have to understand the picture.  Car 1 travels at 35m/s and Car 2 travels at 25m/s.  Based on relative velocities, we can understand that Car 1 travels 10m/s faster than Car 2 every second.  So we can interpret Car 1's relative velocity to Car 2 as 10m/s.  Car 1 needs to travel 10m/s till a point of catching up to Car 2 which is 462m away.

v = 10m/s

d = 462m

v = d/t

(10) = (462)/t

t = 46.2s

So it takes 46.2 seconds for Car 1 to catch up to Car 2, but the question is asking how far does Car 1 travel to catch up.  So we have to use Car 1's velocity and not the relative velocity:

v = 35m/s

v = d/t

(35) = d/(46.2)

d = 1617m

Car 1 traveled a total distance of 1617m.