Question

a train travelling at the speed of 48km/h takes 27 seconds to cross a man standing on a railway platform. find the lenght of the train. hence find the the time taken by the train to cross a bridge 2.64 km long

Answer 1

Dear student
$$\begin{gathered} \mathrm{We}\mathrm{know}, \\ \mathrm{Speed}=\frac{\mathrm{Distance}}{\mathrm{Time}} \\ \mathrm{Length}\mathrm{of}\mathrm{train}=\mathrm{Speed}\mathrm{of}\mathrm{train}\times \mathrm{Time}\mathrm{Taken} \\ =\left(48\times \frac{27}{60\times 60}\right)\mathrm{km}\left[1\sec =\frac{1}{60\times 60}\mathrm{hour}\right] \\ =0.36\mathrm{km} \\ =\left(0.36\times 1000\right)\mathrm{m}\left[1\mathrm{km}=1000\mathrm{m}\right] \\ =360\mathrm{m} \\ \mathrm{Time}\mathrm{taken}\mathrm{by}\mathrm{train}\mathrm{to}\mathrm{cross}\mathrm{the}\mathrm{bridge}=\frac{2.64\mathrm{km}}{48\mathrm{km}/\mathrm{h}}=0.055\mathrm{hour} \end{gathered}$$
Regards