Question

A cyclist starts from the centre O of a circular park of radius one kilometer, reaches the edge P of the park, then cycles along the circumference and returns to the centre along QO as shown in the figure. If the round trip takes ten minute, the net displacement and average speed of the cyclist (in metre and kilometer per hour) is –

• A. 0, 1
• B. $\frac{\pi + 4}{2}$, 0
• C. 21.4, $\frac{\pi + 4}{2}$
• D. 0, 21.4

Answer 1

Answer: (D)

0, 21.4

Answer 2

Q Cyclist returns at initial point

\ Displacement = 0

v_av = $\frac{s}{t} = \frac{R + \frac{\pi R}{2} + R}{(1/6)}$ = 6R (2 + p/2)

= 21.4 km