## Time/Distance II

Q1:

A train running at a speed of 72km/h croses a tree in 9s.What is the length of the train?

Ans: Speed of the train=72km/h

=72x5/18

=20m/s

Length of the train=20x9=180m

Q2:

A train running at a speed of 54km/h croses a tree in 18s.What is the length of the train?

Ans: Speed of the train=54km/h

=54x5/18

=15m/s

Length of the train=15x18=270m

Q3:

A train running at a speed of 108km/h croses a tree in 6s.What is the length of the train?

Ans: Speed of the train=108km/h

=108x5/18

=30m/s

Length of the train=30x6=180m

Q4:

A train of length 600m is passing a electric post near the track in 6s.What is the speed of the train?

Ans: Speed of the train=600/6

=100m/s

=100x18/5

=360km/h

Q5:

A train of length 400m is passing a tree near the track in 20s.What is the speed of the train?

Ans: Speed of the train=400/20

=20m/s

=20x18/5

=72km/h

Q6:

A train of length 300m is passing a electric post near the track in 9s.What is the speed of the train?

Ans: Speed of the train=300/90

=10/3m/s

=10x18/3x5

=12km/h

Q7:

How long does a train 110 m long running at the speed of 72 km/h take to cross a bridge of 130 m length?

Ans: Total distance traveled by the train for crossing the bridge=110+130 = 240 m

Speed of the train=72 km/h

=72 x 5/18 m/s

=20 m/s

Time taken by the train to cross the bridge        = 240/20

= 12 s

Q8:

How long does a train 200 m long running at the speed of 36 km/h take to cross a bridge of 80 m length?

Ans: Total distance traveled by the train for crossing the bridge=200+80 = 280 m

Speed of the train=36 km/h

=36 x 5/18 m/s

=10 m/s

Time taken by the train to cross the bridge=280/10

=28 s

Q9:

How long does a train 140 m long running at the speed of 90 km/h take to cross a platform of 110 m length?

Ans: Total distance traveled by the train for crossing the bridge=140+110 = 250 m

Speed of the train=90 km/h

=90 x 5/18 m/s

=25 m/s

Time taken by the train to cross the bridge=250/25

=10 s