Question

Please help me on this question!

Answer 1

Let's label the two cars as: car 1 and car 2
Car 1 is going 55 km/hr and it is the first one to pass the landmark. Car 2 is going 63 km/hr

Let t be the time that elapsed since car 1 passes the landmark

Car 1 travels for t hours while car 2 travels for t-1 hours
The starting point is the landmark. Once car 1 passes the landmark, the timer starts

The distance equation for Car 1 is
d = r*t
d = 55*t

The distance equation for car 2 is
d = r*t
d = 63*(t-1)

Car 2 will pass car 1 at exactly the point when the distances are the same. Set the distance expressions equal to each other and solve for t
55t = 63(t-1)
55t = 63t-63
55t-63t = -63
-8t = -63
t = -63/(-8)
t = 7.875

Now plug this into t-1 to get
t-1 = 7.875-1 = 6.875

Final Answer: 6.875

So 6.875 hours after car 2 passes the landmark, car 2 will overtake car 1