Express 15 m s−1 in kmh−1.
Given,
Speed = 15 m/s
We have to convert it into km/h
Now,
15 m/s = 15×36001000=15×185=54 km/h
Hence the in km/h its value is 54 km/h
A train travels 40 km at a uniform speed of 30kmh−1. Its average speed after travelling another 40 km is 45kmh−1 for the whole journey. Find its speed in the second half of the journey.