Moving problem?

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1 Answer
Jun 17, 2018

I tried this although my interpretation of the question may be wrong....

Explanation:

I am not sure but reading the question it seems to imply that the two cars start with a certain speed regardless to the fact that they should start from rest and accelerate up to reaching a certain speed...!
Let us consider this....strange situation and say the the two speeds are s_1s1 and s_2s2 with:

s_2=2s_1s2=2s1 ...........................................(1)

the time will be: t=6ht=6h; during this time the first car will travel a distance d_1d1 while the second d_2d2 such that:

d_2-d_1=204"mi"d2d1=204mi............................(2)

we know that:

"speed"="distance"/"time"speed=distancetime

so we get:

s_1=d_1/ts1=d1t
s_2=d_2/ts2=d2t

let us combine the two equations through tt:

d_1/s_1=d_2/s_2d1s1=d2s2
and using (1)

d_1/cancel(s_1)=d_2/(2cancel(s_1))

so that:

d_2=2d_1

into (2):

2d_1-d_1=204"mi"

and: d_1=204"mi"
giving:
d_2=204+204=408"mi"

so the speeds will be:

s_1=204/6=34"mi"/h
s_2=408/6=68"mi"/h