17. (i) The speed of train is 30km/h. How long will it take to cross a

1.	17. (i) The speed of train is 30km/h. How long will it take to cross a signal if its length is 25m.
Answer» Given: Speed of Train = 30km/h LENGTH of Train = 25m Find: TIME Taken To Cross A Signal Formula USED: $\underline{ \boxed{ \red ⇨ \rm \color{blue}Distance = \frac{Speed}{Time}}}$ Solution: Here, we have to find the time So, we, KNOW that, $\underline{ \boxed{ \blue ⇻\rm \color{orange}Distance = \frac{Speed}{Time}}}$ where, ➧ Speed = 30km/hr $\rm = 30 \times \frac{5}{18} m/s$ $\rm = \frac{150}{18} m/s$ ➧ Distance = Length of the train = 25m Now, $→ \rm Distance = \frac{Speed}{Time}$ $→ \rm Distance = \frac{25}{ \frac{150}{18} }$ $→ \rm Distance = \frac{25 \times 18}{150}$ $→ \rm Distance = \frac{ 25\times \cancel{ 18}} { \cancel{150}}$ $→ \rm Distance = 25 \times 0.12 = 3$ $→ \rm Distance = 3sec$ HENCE, The Time Taken By train to cross a signal will be 3sec