Question

A train passes over a 200 m long bridge in 10 sec. The length of the train is 100 m. The speed of the train is

• A. $10\frac{m}{s}$
• B. $30\frac{m}{s}$
• C. 0.86 $\frac{m}{s}$
• D. 1.42 $\frac{m}{s}$

Answer 1

The correct option is B

$30\frac{m}{s}$

Step 1: Given data

Length of the bridge = 200 m

Length of the train = 100 m

Time taken to cross the bridge t=10 sec

Let us consider the speed of the train as S.

Step 2: Calculation of speed

Speed is defined as the distance traveled by an object per unit interval of time.

so, speed =$\frac{dis\tan ce}{time}$

Here, total distance traveled by train = length of the train+ length of the bridge

therefore,

speed S = $\frac{100+200}{10}$

=$\frac{300}{10}$

S= $30\frac{m}{s}$

Hence,

The speed of the train is $30\frac{m}{s}$.Hence option (b) is the correct answer.