Question

7. Two trains whose length difference is 170 m, crosses each other in 16 sec when moves in opposite direction but
crosses each other in 36 sec when move in the same direction. Find the speed of faster train if speed of slower
train is 35 km/hr.
दो रेलगाड़ी में से एक की लम्बाई दूसरी रेलगाड़ी की लम्बाई से 170 मीटर अधिक है विपरीत दिशाओं में चलती हुई ये एक
दूसरी को 16 सेकंड में और समान दिशा में चलती हुई 36 सेकंड में पार कर जाती है यदि धीमी गति वाली रेलगाड़ी की
चाल 35 किमी/घंटा हो तो तेज गति वाली रेलगाड़ी की चाल क्या होगी?
a)98 km/hr
b)70 km/hr
d)91 km/hr
d)65 km/hr​

Answer 1

Answer:

d)91 km/hr

Step-by-step explanation:

The distance travelled by an item per second is its absolute speed. The change in distance between two objects per second indicates how fast one thing is moving in relation to another. The speed of two moving objects in relation to one another is the same. If two trains or bodies are travelling at u m/s and v m/s in the same direction and u>v, the relative speed in the same direction is equal to (u - v) m/s. If two objects, such as two trains, are travelling at u m/s and v m/s in the opposite directions, then their relative speed is equal to (u + v) m/s.

$\begin{aligned} & \text { Length of First Train }=L_1 \\ & \text { 2nd Train } \Rightarrow L_1+170\end{aligned}$

II same Direction Relative speed $\Rightarrow(x-35) \mathrm{km} / \mathrm{hr}$

$\left\{s=\frac{D}{T} \quad(x-35) \times \frac{S}{18}=\frac{L_1+L_1+170}{36}\right.$

$(x-35) \times \frac{5}{18} \times 36=2 L_1+170$

$(x-35) 10=2 L_1+170.....(1)$

opposite Dizection Relative speed $=2(x+3 S) \mathrm{km} / \mathrm{kr}$

$\begin{aligned}& (x+35) \times \frac{5}{18}=\frac{4_1+L_1+170}{16} \\& (x+35) \times \frac{5}{18}=\frac{24_1+170}{16}\end{aligned}$

$\begin{aligned}& x+35 \times \frac{5}{18} \times 16=(x-35) 10 \\& x+35 \times \frac{5}{18} \times \frac{16}{10}=x-35\end{aligned}$

$\begin{gathered}4 x+140=9 x-315 \\5 x=455\end{gathered}$

$x=91 km/hr$

Learn more about similar questions visit:

https://brainly.in/question/835838?referrer=searchResults

https://brainly.in/question/47056386?referrer=searchResults

#SPJ1