4.9 A cyclist starts from the centre O of a circular park of radius 1 km, reaches the edge P of the park, then cycles along the circumference, and returns to the centre along QO as shown in Fig. 4.21. If the round trip takes 10 min, what is the

(a) Net displacement

(b) Average velocity

(c) Average speed of the cyclist?

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1 Answer

Answered by

Vishal Baghel | Contributor-Level 10

5 months ago

4.9

(a) Since the cyclist came back to his starting point O, so the displacement is Zero

(b) Average velocity = $\frac{n e t d i s p l a c e m e n t}{t i m e t a k e n} = \frac{0}{t i m e t a k e n}$ = 0

(c) Average speed = $\frac{d i s t a n c e t r a v e l l e d}{t i m e t a k e n}$

Distance travelled = OP + PQ + QO

= 1 + (1/4) $* 2 * (\frac{22}{7}) * 1 + 1 =$ 3.57 km

Average speed = 3.57 / 10 km/min = 21.43 km/h

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