train qs
Q1.Two trains with speeds 65m/sec and 40m/sec are traveling in the same direction. The train with the higher speed is of shorter length than the other. It can completely overtake the other train in 20 sec. Now, if they travel in opposite directions and meet at point A, then the slower train takes 4.425 sec extra to pass the point A after faster train passes it. What is the difference between the length of the two trains?
a. 500m b. 300m c. 100m d. None of these
Q2.Two trains are on a collision course, each moving at 60kmph. They are separated by a distance 10mk. A bird starts flying from train A to train B. As soon as it reaches B, it starts flying back to A, then back to B and so on. What is the total distance traveled by the bird before the two trains collide, if the speed of the bird is 90kmph?
a. 6.25km b. 7 km c. 7.5 km d. None of these
Q2.Two trains are on a collision course, each moving at 60kmph. They are separated by a distance 10mk. A bird starts flying from train A to train B. As soon as it reaches B, it starts flying back to A, then back to B and so on. What is the total distance traveled by the bird before the two trains collide, if the speed of the bird is 90kmph?
a. 6.25km b. 7 km c. 7.5 km d. None of these
two train meet secondtime after 5 min
birds relative speed=90+60-60=90
so in 5 min bird traveled 7.5km
Little Star
n/a
sum of length of bothn both the trains=(65-40)*20=500m
time taken to pass point a= 500/(40+65) =4.7sec
now , dis. covered by slower train in 4.7 sec = 4.7*40 = 188 m
now , dis. covered by slower train in 4.425 sec = 4.425*40 = 177 m
now length of slower train = 188+177=365 m
difference b/w length of trains=500-365=135 m
- posted by OM RAWAT
and assistent ASHOK KHANDELWAL
AND PEON PANKAJ GOYAL
let L1 be the length of faster train and L2 of slower one.
now L1+L2 = (65-40)*20 = 500 meters
again if these trains run in opposite directions then time taken by the faster train to pass point A
t = L1/65
and time taken to pass point A by slower train is
t+4.425= L2/40
now repacing the value of t
L1/65 + 4.425 = L2/40
thus
(500-L2)/65 + 4.425 = L2/40
500/65 + 4.425 = L2(1/40 + 1/65)
L2 = 40 * 65 *(500/65+4.425)/105
= 300.02
= 300
L2 - L1 = 300 - (500 - L2)
= 300 - 500 +300
= 100 meters
Q1.Two trains with speeds 65m/sec and 40m/sec are traveling in the same direction. The train with the higher speed is of shorter length than the other. It can completely overtake the other train in 20 sec. Now, if they travel in opposite directions and meet at point A, then the slower train takes 4.425 sec extra to pass the point A after faster train passes it. What is the difference between the length of the two trains?
a. 500m b. 300m c. 100m d. None of these
first train L1=65/ssec
second train L2=40/sec
from data, (L2-L1)/25=20
so L2-L1=500m
Little STar
n/a
n/a