A jogger running at 9 km h- 1 alongside a railway track is 240 metres ahead of the engine of a 120 metre long train running at 45 km h- 1 in the same direction. In how much time will the train pass the jogger?

Question

A jogger running at 9 km h- 1 alongside a railway track is 240 metres ahead of the engine of a 120 metre long train running at 45 km h- 1 in the same direction. In how much time will the train pass the jogger? (A) 3.6s (B) 18 s (C) 36 s (D) 72 s

Tardigrade Admin · Accepted Answer

Speed of train relative to jogger =(45-9) km h -1=36 km h -1 =(36 × (5/18)) m s -1=10 m s Distance to be covered =(240+120) m =360 m. ∴ Time taken =((360/10)) s =36 s

Q. A jogger running at $9 km h^{- 1}$ alongside a railway track is $240$ metres ahead of the engine of a $120$ metre long train running at $45 km h^{- 1}$ in the same direction. In how much time will the train pass the jogger?

$3.6 s$

$18 s$

$36 s$

$72 s$

Speed of train relative to jogger $= (45 - 9) km h^{- 1} = 36 km h^{- 1}$ $= (36 \times \frac{5}{18}) m s^{- 1} = 10 m s$
Distance to be covered $= (240 + 120) m = 360 m$ .
$∴$ Time taken $= (\frac{360}{10}) s = 36 s$

Q. A jogger running at 9kmh−1 alongside a railway track is 240 metres ahead of the engine of a 120 metre long train running at 45kmh−1 in the same direction. In how much time will the train pass the jogger?

3.6s

18s

36s

72s