Question

A 150m long train is moving with constant velocity of 12.5 m/s. Find
i) the equation of the motion of the train.
ii) time take to cross a pole.
iii) the time taken to cross the bridge of length 850m is?​

Answer 1

Answer:

Step-by-step explanation:

Given  

A 150 m long train is moving with constant velocity of 12.5 m/s. Find i) the equation of the motion of the train.ii) time take to cross the pole and time taken to cross the bridge 850 m long

Given length of the train is 150 m

Length of the bridge = 850 m

Now total distance travelled by train will be 850 + 150 = 1000 m

Given velocity of train is 12.5 m/s

We know that velocity = displacement / time

Now time taken to cross the pole will be

        12.5 = 150 / t

So t = 150 /12.5

So t = 12 seconds.

Now we need to find the time taken to cross the bridge

     So             12.5 = 1000 / t

So t = 1000 / 12.5

So t = 80 secs

So it will take 80 seconds to cross the bridge.

Answer 2

Answer:

Time need to cross the pole by train = 12 second

Time taken to cross the bridge of length of 850 m is 80 second

Step-by-step explanation:

Data:

Distance = d = 150 m  

velocity = v = 12.5 m/s

Required:

1) Time take to cross the pole = t = ?

2) Time take to cross the bridge of length 850 m = t = ?

Calculation:

We know that

The velocity of body = Distance / time

Since train has to cross the pole so the distance cover by the train to cross the pole is equal to length of train

Putting values in the formula we get

              12.5 = 150 / t

                    t = (150) / 12.5 = 12‬ s

So time need to cross the pole by train = 12 second

And

When train has to cross the bridge of length 850 m then

Total distance = D = 150 m + 850 m = 1000 m

Putting the values we get

velocity = distance / time

     12.5 = 1000 / t

           t = 1000 / 12.5  = 80 s

Thus time taken to cross the bridge of length of 850 m is 80 second