Physics

Problem

A train starts from station A (taken as origin) and travels along a straight track as follows: (i)

15\,\text{min}

60\,\text{km\,h}^{-1}

east, (ii)

10\,\text{km}

east in

8\,\text{min}

, (iii)

12\,\text{min}

30\,\text{km\,h}^{-1}

west, (iv)

4\,\text{km}

west in

4\,\text{min}

. Which one of the following pairs correctly gives its average speed and the magnitude of its average velocity for the entire journey? a)

35.0\,\text{km\,h}^{-1};\;23\,\text{km\,h}^{-1}

53.8\,\text{km\,h}^{-1};\;0\,\text{km\,h}^{-1}

53.8\,\text{km\,h}^{-1};\;23\,\text{km\,h}^{-1}

23.0\,\text{km\,h}^{-1};\;23\,\text{km\,h}^{-1}