Question

A cyclist goes around a circular track once every 2 minute .If the radius of the circular track is 105 meters calculate his speed?
$\pi = 22/7$
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Answer 1

SoLuTiOn :

➡ Given:

✏ Time requires to cover distance equal to perimeter of circular path = 2min

✏ Radius of circular path = 105m

➡ To Find:

✏ Speed of cyclist ??

➡ Concept:

✏ Speed is defined as distance covered by body in unit time.

$\star \: \underline{ \boxed{ \bold{ \rm{ \pink{v = \frac{distance}{time}}}}}} \: \star$

➡ Conversation:

✏ 2 min = 120 s

➡ Calculation:

$\mapsto \rm \: v = \frac{2\pi \times r}{t} \\ \\ \star \: \rm{ \tiny{r = radius \: of \: circular \: path}} \\ \\ \mapsto \rm \: v = \frac{2 \times 22 \times 105}{7 \times 120} \\ \\ \mapsto \rm \: v = \frac{4620}{840} \\ \\ \mapsto \: \underline{ \boxed{ \bold{ \rm{ \purple{v = 5.5 \: \frac{m}{s} }}}}} \: \star \star$

Answer 2

$\mathtt{ \huge{\fbox{Solution :)}}}$

Given ,

• Distance = circumference of circle( 2πr) = (2 × 22/7 × 105) m

• Time = 2 min or 120 sec

We know that , the ratio of distance per unit time is called speed

$\large \mathtt{ \fbox{Speed = \frac{distance}{time} }}$

Substitute the known values , we get

$\sf \mapsto Speed = \frac{ \cancel2 \times 22 \times \cancel{105}}{ \cancel7 \times \cancel{120}} \\ \\\sf \mapsto Speed = \frac{22 \times \cancel{15}}{ \cancel{60}} \\ \\\sf \mapsto Speed = \frac{22}{4} \\ \\ \sf \mapsto Speed = 5.5 \: \: m/sec$

Hence , the speed is 5.5 m/s

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