Question

D. O 6% Reset 59. Find the time taken by a 320 m long train running at 54 km/hr to cross a girl standing on the platform S: A A 32 seconds B. O 27.67 seconds a CO21.33 seconds D. 24 seconds.​

Answer 1

Answer:

Let the time taken to cross the man standing on the platform be = x

We know that :

\begin{gathered}\tt{Speed = \frac{Distance}{Time}}\\\end{gathered}Speed=TimeDistance

Put the values in the formula, but before, convert 54 km/hr into m/s so that all the quantities are in the same units

54 km/hr = \begin{gathered}\tt{\frac{54\times5}{18}}\\\end{gathered}1854×5

54 km/hr = 15 m/s

Put this value into the formula :

\begin{gathered}\tt{15 = \frac{180}{x}}\\\end{gathered}15=x180

=》 \begin{gathered}\tt{x = \frac{180}{15}}\\\end{gathered}x=15180

=》 \tt{x = 12 s}x=12s

Thus, the time taken is 12 seconds