A train moving at 49 mph meets and is passed by a train moving at 63 mph. A passenger in the first t

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18 Sep 2015 Train length

A train moving at 49 mph meets and is passed by a train moving at 63 mph. A passenger in the first train noted that the second train took 4.5 seconds to pass him. How long is the second train?

OPtion

1) 840 ft
2) 854.57 ft
3) 746.75 ft
4) 764.46 ft
5) 576.76 ft
6) 400 ft
7) 740.46 ft
8) 700 ft
9) 724 ft
10)None of these

Solution

162 5289 x (49 + 63) x 4.5
60 x 60
= 740.46 ft

Option 7)

Correct Option: 7 Best Solution (10)

Abhinav Akash   9 years AGO

The effective speed between the trains: 49 + 63 = 112 mph
Assume the passenger is stationary and the 2nd train is passing him at 112 mph.
1 mile= 5280 foot.
1 hour= 3600 secs.
(112*5280/3600)*4.5=739.5 ft.

Like? Yes (31) | No (6)  

AKASH   9 years AGO

The effective Relative speed between two trains is 49 + 63 = 112 mph
Now by Assuming that passenger is stationary and the 2nd train is passing him
at 112 mph than by
Finding the speed in ft/sec and multiplying it by 4.5
((112*5280)/3600)* 4.5 = 739.5 ft
HENCE THE ANSWER IS 740(approx) the length of the second train.

Like? Yes (4) | No (4)  

naveen   9 years AGO

LENTH of the train=((49+63)*5280*4.5)/3600
~740

Like? Yes (5) | No (5)  

SAGNIK DATTA   9 years AGO

((49+63)*(4.5/3600))*5280 miles

Like? Yes (2) | No (4)  

Kethineni Vinodh   9 years AGO

The effective speed between the trains: 49 + 63 = 112 mph
Assume the passenger is stationary and the 2nd train is passing him
at 112 mph
:
speed in ft/sec, mult by 4.5 sec: (112*0.44704m/s)*4.5sec
=739.5 ft is the length of the train

Like? Yes (4) | No (6)  

Arnab Maity   9 years AGO

The relative speed between the trains: 49 + 63 = 112 mph
Assume the passenger is stationary and the 2nd train is passing him
at 112 mph
Therefore, the length of the train = 112/3600*4.5 = 0.14m = 739.2 ft

Like? Yes (4) | No (6)  

SHAIK MAHABOOB BASHA   9 years AGO

from the problem we notice that the trains are travelling opposite to each other so relative speed of two trains are (49+63)112mph
we convert mph into feet per sec then we get 164.266666667 and then we multiply 4.5 secondswe get 739.2

Like? Yes (2) | No (5)  

anuj   9 years AGO

we have two trains moving in opposite direction...so,their speed will add. after that we need to find answer in feet so as we know in 1 mile=5280 feet.
convert the speed in feets per sec.Now we have speed and time ,just find the distance:)

Like? Yes (4) | No (7)  

gyanesh Patel    9 years AGO

1. If they trains are traveling away from each other he observes the train at a relative velocity of 112 mph (63 + 49) 2. To get the answer we must multiply the velocity times the time. 3. The hardest part about this problem are the units. 4. Convert mph to feet per sec, then multiply times 4.5 sec to get the answer in feet. Answer= 739.2 feet

Like? Yes (4) | No (7)  

praveendas   9 years AGO

x/112=4.5/3600.
we can get length in km.
convert it in t0 ft

Like? Yes (1) | No (6)