A train is uniformly accelerated and passes Successive kilometre Stones with velocities of
18 km/h and 36 km/h respectively
, calculate
the velocity, when it passes the third kilometre
Stone. Also find the time taken for each of
these two intervals of one kilometre​

Explanation:

18 km/hr(1000 m/km) / (3600 s/hr) = 5 m/s

36 km/hr = 10 m/s

v² = u² + 2as

a = (v² - u²)/2s

a = (10² - 5²)/2(1000) = 0.0375 m/s²

v² = 10² + 2(0.0375)(1000)

v² = 175

v = 13.22875... ≈ 13 m/s ≈ 48 km/hr

v = u + at

t = (v - u) / a

t = (10 - 5)/0.0375 = 133.333... 133 s

t = (13.22875 - 10) / 0.0375 = 86.1 s

wavelength variability is the right one