A train of length l, traveling at a constant velocity, passes a pole in t seconds .If the same train traveling at the same velocity passes a platform in 3t seconds, then the length of the platform is-------

Description (বিবরণ) :

প্রশ্ন: A train of length l, traveling at a constant velocity, passes a pole in t seconds .If the same train traveling at the same velocity passes a platform in 3t seconds, then the length of the platform is-------

ব্যাখ্যা:

Total time difference  =  3t - t  =  2t
In time t second train passed l length
⸫ "  "  1   "       "      "  $\frac{l}{t}$ length
⸫ "   "  2t  "      "       "   $\frac{l\times 2t}{t}$  "
 =  21  "
Travelling distance  =  length of train   +   length of platform
⇒ 2l  =  1   +   length of platform
⸫ length of platform  =  2l  -  1  =  1