Question

A train $320m$ long is travelling at a uniform speed of $66km/hr.$ If it passes a platform is $42$ seconds, find the length of the platform .

Answer 1

Let $x$ be the length of platform $\left(d_1\right)$.

Length of train $\left(d_2\right)=320m$

Speed of train $\left(s\right)=66km/h=66\times \frac{5}{18}=\frac{55}{3}m/s$

Time taken to pass the platform $\left(t\right)=42s$

Now, as we know that

$t=\frac{d_1+d_2}{s}$

$42=\frac{320+x}{\left(\frac{55}{3}\right)}$

$\Rightarrow 320+x=\frac{55}{3}\times 42$

$\Rightarrow x=770-320=450m$

Hence the length of the platform is $450m$.