A train 100 m long is running at the speed of 30 km/hr. Find the time taken by it to pass a man standing near the railway line.
A. 10 sec.
B. 12 sec.
C. 14 sec.
D. 16 sec.
Solution
Speed of the train
= (30 x 5/18)m/sec
= (25 / 3) m/sec.
Distance moved in passing the standing man
= 100 m.
Required time taken
= 100 /( 25 / 3)
=(100 x 3 / 25) sec
Speed of the train
= (30 x 5/18)m/sec
= (25 / 3) m/sec.
Distance moved in passing
the standing man
= 100 m.
Required time taken
= 100 /( 25 / 3)
=(100 x 3 / 25) sec
= 12 sec.
ANSWER IS (B) = 12 sec.
2.
A man sitting in a train which is travelling
at 50 kmph observes that a goods train, travelling in opposite
direction, takes 9 seconds to pass him. If the goods train is 280 m
long, find its speed?
A. 52 kmph.
B. 62 kmph.
C. 72 kmph.
D. 80 kmph.
Solution
Relative Speed
= (280 / 9)m/sec
= (280/9 x 18/5)
= 112 kmph.
Speed of the train
= (112 - 50)kmph
= 62 kmph.
ANSWER IS (B) = 62 Kmph.
3.
A train 150 m long is running with a apecd of
68 kmph. In what time will it pass a man who is running at 8 kmph in
the same direction in which the train is going?
A. 6 sec.
B. 7 sec.
C. 9 sec.
D. 11 sec.
Solution
Speed of the train relative to man
=( 68 - 8 )
= 60 Kmph
= 60 x 5 / 18
=50/3 m/sec.
Time taken by it to cover 150 m at (50 /3)m/sec
= (112 - 50)kmph
= (150 x 3/50)sec
= 9 sec.
ANSWER IS (C) = 9 sec.
4.
A train moves with a speed of 108 kmph. Its speed in metres per second is
A. 10.8
B. 18
C. 30
D. 38.8
Solution
Speed
= 108 Kmph
= (108 x 5/18)m/sec
= 30 m/sec.
ANSWER IS (C) = 30
5.
Two trains travel in opposite directions at
36 kmph and 45 kmph and a man sitting in slower train passes the faster
train in 8 seconds. The length of the faster train is
