A cyclist covers the following four successive segments:

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A cyclist covers the following four successive segments: (i)

2\,\text{km}

east at

12\,\text{km/h}

, (ii)

3\,\text{km}

north at

12\,\text{km/h}

, (iii)

4\,\text{km}

west at

6\,\text{km/h}

, and (iv)

3\,\text{km}

south at

6\,\text{km/h}

. Which of the following pairs gives the correct values of (average speed ; magnitude of average velocity) for the entire journey? (a)

(7.6\,\text{km/h} ; 7.6\,\text{km/h})

(b)

(9.0\,\text{km/h} ; 9.0\,\text{km/h})

(c)

(7.6\,\text{km/h} ; 1.3\,\text{km/h})

(d)

(7.6\,\text{km/h} ; 2.0\,\text{km/h})