Question

trains A and B are traveling in the same direction on a parallel track. train A is traveling at 40 miles per hours and train B is traveling at 50 miles per hour. train a passes a staion at 7:25 pm. if train B passes the same station at 7:37 pm at what time will train B catch up to train A?

Answer 1

i came up with diff answers so im not for sure i got 8:25

Answer 2

725-737= is 12 min difference in the two

Answer 3

thats 1/5 of an hour

Answer 4

let t1hrs be the time for train A (speed 40 mph) to reach 'catching' point
and t2 hrs for train B (speed 50 mph).

Since A started 12 minute earlier t1=t2+12

now since both travelled same distance in reaching the catching point
t1 * s1 = t2 * s2
(t2+12)*40 = t2*50
t2= 48 hrs
Ans: 48 hrs after 7:37 pm i.e. 2 days after, at the same time.

Answer 5

mult. 1/5*40=8 miles
40-8=32 miles difference

Answer 6

so exactly what is the ans

Answer 7

theres 10 mph difference in the two

Answer 8

so tena32 at what time with train b catch up with train a

Answer 9

im getting 8:25

Answer 10

what approach did you follow?

Answer 11

let me type it

Answer 12

ok

Answer 13

2:37-2:25= 12 min diff in the two trains which is 1/5 hour
the difference in speed is 10 (50-40)
1/5*40=8

Answer 14

tena32 is it 8:25 am

Answer 15

it is not that simple

Answer 16

i know

Answer 17

it is 8.25pm

Answer 18

thnks

Answer 19

no this problem is horrible ive had my niece work it and she is in honors in college and she had troublr

Answer 20

i still have like 3 more word problems to go lol

Answer 21

@tan1992: what is the solution?

Answer 22

ok i try my best to explain

Answer 23

yall gonna love me by the time im done lol

Answer 24

@tena32: It is not that horrible as well. Just that I have been out of touch

Answer 25

heu o got 8:25 too

Answer 26

i will write it out nicely and post it k?

Answer 27

train b is 10 mile faster than train a per hour
train a reach station at 7.25 while train b reach 7.37 which mean when train reach the station train a is moving at 40 mile per hour for 12 min= 8 MILE
since b can catch up a 10 mph ,then it take 48 MIN to catch up 8 mile
7.37pm+48min=8.25

Answer 28

thats it tan. i was on the right track no pun intended

Answer 29

since b can catch up a 10 mph ,then it take 48 MIN to catch up 8 mile

@tan1992: Please Explain?

Answer 30

mean train b faster than train a 10 mile per hour
we use 8 mile dive by 10mph we will get 0.8 which mean train b need 0.8 hour to catch up train a

Answer 31

*devide

Answer 32

i got excited so i hope you can read it

Answer 33

i made equation for each train
and i found when train B will catch up to train A by setting these equations equal

Answer 34

@myininaya: which co-ordinate system are you using?
position - time ?

Answer 35

rectangular

Answer 36

cartesian

Answer 37

time is x axis
position is y
right!

Answer 38

does it make sense?
do i need to explain anything?

Answer 39

@Myininnaya: how did you arrive at the equations of line

Answer 40

@tan1992: I still am not sure if we could use the difference in speed of both the trains i.e. 10 mph to find anything in this problem unless we are using relative motion.

Answer 41

train A
time=t
t0=0
t1=0+40
t2=40+40
...
tx=40x

train B
time=t
t0=0
t1=0+50
t2=50+50
....
tx=50x
but they want to know from the when they hit that station
so
train A has position y=40x+445/60
445/60 is 7:25 in minutes
train B has position y=50x+457/60

Answer 42

since 457/60 minutes=7:37

Answer 43

50x+457/60=40x+445/60
gives x=101/12=8 25/60 =8:25

Answer 44

tx means at time x

Answer 45

@myininaya:: y denotes a position. right?
So for A, y= 40x + ---- (you used 445/60 min which is a time quantity)
can you add to different units to obtain y( a position)?

Answer 46

oops by the way those lines above were meant to be
y=40x-445/60
and y=50x-457/60
sorry for type-0
aclan give me a second
it might help if i explain both parts together

Answer 47

@myininaya:: And does the slope of position-time graph give speed? As I can recall, it was distance - time graph.

Answer 48

my explanation is sort of bad above but...
okay we aren't looking at the station right now okay?
train A
at time 0 hour, the position is 0
at time 1 hour, the poisiton is 40
at time 2 hour, the position is 40+40=40(2)
at time 3 hour, the position is 40+40+40=40(3)
...
at time x hour, the position is 40x
now lets keep the station in mind now
so if we draw the position 0 is at hour 7 25/60 then we are on the x-axis
so we have a line y=mx+b
we know a point on the line (7 25/60,0) and m=40
0=40*445/60+b
so the y intercept is -40*445/60
so the position of train A is y=4x-40*445/60
the position of the train is only changing due to speed of the train and they give us this in the problem the train is traveling 40 miles per hour

Answer 49

similiary we can do the same process for train B

Answer 50

the position is y=speed*time-blah

Answer 51

a clan do you understand the train is moving due to the speed right?

Answer 52

at time 0, we are at position 0
at time 1, we are at poistion 0+40
...
time x, we are at position 40x
do you not undestand this part?

Answer 53

x is time

Answer 54

I understand

Answer 55

the train is moving 40 miles every hour

Answer 56

so final answer would be----?

Answer 57

lol 8:25 same as what i got along itme ago