Question

A train travelling at a speed of 72 km/hr crosses a bridge in 30 seconds. If the length

of the train is 250 m, find the length of the bridge​

Answer 1

Answer:

$\bigstar{\bold{Length\:of\:bridge=350\:m}}$

Step-by-step explanation:

$\Large{\underline{\underline{\bf{Given:}}}}$

• Speed of the train = 72 km/hr = 20 m/s
• Time taken = 30 s
• Length of the train = 250 m

$\Large{\underline{\underline{\bf{To\:Find:}}}}$

• Length of the bridge

$\Large{\underline{\underline{\bf{Solution:}}}}$

→ Let the length of the bridge be x m

→  Hence the total distance to travel = x + 250 m

→ We know that the distance travelled is given by the equation,

  Distance = Speed × Time

→ Substituting the datas we get,

  x + 250 = 20 × 30

  x + 250 = 600

  x = 600 - 250

  x = 350 m

→ Hence the length of the bridge is 350 m

$\boxed{\bold{Length\:of\:bridge=350\:m}}$

$\Large{\underline{\underline{\bf{Notes:}}}}$

→ Speed is defined as the distance travelled per unit time. It's unit is m/s.

→ Speed is a scalar quantity. That is it has only magnitude and no direction.

→ Speed = Distance/Time

→ Time = Distance/Speed

→ Distance = Speed × Time