Question

A train 100m long is moving with a velocity of 60 km/hr ind the time it takes to cross the
bridge 1km long.​

Answer 1

Appropriate question:

• A train 100m long is moving with a velocity of 60 km/hr find the time it takes to cross the bridge 1km long.

Given information to us:

• What's the length of the train ? = 100m
• What's the length of the bridge ? = 1km
• Velocity = 60 km/hr

What is the need to solve and calculate ?

• Time which had been taken to cross the bridge by the train.

Formula need to be applied:

• $\boxed{\bf{Time = Distance / Speed}}$

Solving way:

»» First of all we have to find the total distance which had been travelled by the train that would be calculated by adding up the values of length of bridge and train. Further we would find the speed in which train had been travelling by multiplying velocity by 5/18.

»» After that we would calculate the time which would be calculated by applying the values in the formula.

Calculations:

★ Here we are calculating the total distance travelled by adding both the length of train and bridge but first we would convert the length of bridge which is in kilometres into metres:

( We know : 1 km = 1000 m)

Thus length of bridge in metre is 1000 m.

Solving :

$:\implies$Total distance = 1000 + 100

$:\implies$ Total distance = 11000m

★ Calculating the speed:

$:\implies$ Speed = 60 × 5/18

$:\implies$ Speed = 30 × 5/9

$:\implies$ Speed = 10 × 5/3

$:\implies$ Speed = 50/3

★ Here we are calculating the time taken by the train to cross 1km long bridge:

$: \implies$ Time = Distance / Speed

Substituting values:

$:\implies$ Time = 1100 ×3 / 50

Cancelling terms:

$:\implies$ Time = 110 × 3 / 5

$:\implies$ Time = 22 × 3

$:\implies$ Time = 66 s$\:$

Answer:

• Time taken by bridge is 66 s