If 2 cars are travelling in the same direction and .... - page 3

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tara:

It`s not your English, it1`s your miiтd. It`s OK. имхенько
You're so nice. It's already second times you are insulting me. It's the last time.
 
angevoyageur:
You're so nice. It's already second times you are insulting me. It's the last time.


Понял, не дурак.

В мои действия можете вмешиваться, как сочтете нужным.

 
tara:


Понял, не дурак.

В мои действия можете вмешиваться, как сочтете нужным.

If you are going to post on this English language Forum please do so in English . . .
 
RaptorUK:
If you are going to post on this English language Forum please do so in English . . .


Неправильно. Правильно:

Speak English, please.

 
SDC:

This is related to movement of indicators but is easy to write with cars.

Two cars travelling in the same direction car A is 10 miles behind car B, Car A is travelling 2x faster than car B. How many miles further down the road will Car A catch up with car B. The answer is 10 miles.

But if car A is travelling 3x faster the answer is 5 miles.

4X faster is a little over 3 miles (rough calculation in my head)

It looks like I should be able to use a formula to calculate that but I am not seeing it.


incorrect answer 10 miles

you can read it like A is moving every second 2 (m/s)*x (s) + 0 (m) ( at x seconds they pass )

B is then at 1 (m/s) *x(s)+ 10000 (m) when A has moved 10000 meter then B is 5000 meter further

if A catch up with B then 2*x = k and x + 10000 = k so 2*x = x + 10000

car B has moved another 10000 meters before A is at the same distance as B

answer has to be car A has to move 20 miles further down the road will Car A catch up with car B

 

Yes car A does move 20 miles but I meant from position of Car B. I should have said how much further down the road does car B get before car A catches up with it

Car A is at mile 5

Car B is at mile 15.

Car A is moving 2x carB

MILES123456789101112131415161718192021222324252627282930
CAR AA0A1A2A3A4A5A6A7A8A9A10
CAR BB0B1B2B3B4B5B6B7B8B9B10
 
Previously answered
y1 = m1 x + b1     // Car A
y2 = m2 x + b2     // Car B
y1-y2 = (m1-m2)x + (b1-b2) = 0 // at cross
 x = (b2-b1) / (m1-m2)         // when cross
                               // b2-b1 = 10 miles

B1=5 B2=15 M1=2M2 saying A moves 2x B is not enough, you also need to know B's speed. (if neither is moving or both are moving left they never cross.)

Per your box if B0 @ mile 15 and B10 @ mile 25 means B is moving 10 miles per unit time (seconds, minutes, hours) then you have m2 = 1 = 10 miles/10 time units.

when = (b2-b1) / (m1-m2) = (15-5)/(20-10) = 10 (miles) /10 (miles/Time) = 1 Time unit. Where = 10 (miles/Time) * 1 (time unit) + 15 = 25 == 20 * 1 + 5

 

Both are moving same direction there is no defined speed, they can stop and start they can speed up and slow down but when one stops so does the other, when one slows down so does the other but we never know when they will speed up slow down or stop all we know is when one does, the other one does too. And when B moves, A moves x times as much. They never move left.

I know this was already answered with the solution, I was just responding to deVries comment.

 
SDC: there is no defined speed,
The there is no defined answer.
 

There is. User123 and angevoyageur provider the solution.

d/(x-1)

d is the initial distance between the cars. x-1 is the velocity of car A relative to car B

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