Question

24. A man walks around a circular park 4 times in 12 minutes. The radius of the park is 49 m. Find the speed of the
man in km/h. (use t = 22/7)
Brain Stimulants​

Answer 1

Answer:

speed= distance÷tike

speed = .31÷ 0.2

Speed= 1.55 km/h

Answer 2

Given:

A man walks around a circular park -

• 4 times

WIth duration -

• 12 minutes

The radius of the park -

• Radius = 49 m

What To Find:

We have to -

• Find the speed of the man in km/h.

How To Find:

To find speed, we have to -

• First, find the circumference of the circle.
• Next, find the distance the man has covered.
• Third, convert the distance to km.
• Fourth, convert the time to h.
• Finally, find the speed of the man.

Solution:

• Finding the circumference of the circle.

We know that -

$\sf \to Circumference = 2 \pi r$

Substitute the values,

$\sf \to Circumference = 2 \times \dfrac{22}{7} \times 49$

Cancel 7 and 49,

$\sf \to Circumference = 2 \times 22 \times 7$

Multiply 2, 22 and 7,

$\sf \to Circumference = 308 \: m$

• Finding the distance the man has covered.

We know that -

The man has covered 4 rounds.

So we will -

$\sf \to Distance = 4 \times Circumference$

Substitute the values,

$\sf \to Distance = 4 \times 308$

Multiply 4 with 308,

$\sf \to Distance = 1232 \: m$

• Converting the distance in km.

We know that -

$\sf \to Distance = 1232 \: m$

We also know that -

$\sf \to 1 \: km = 1000 \: m$

So, we will -

$\sf \to Distance \: in \: km = \dfrac{1232}{1000}$

Divide 1232 by 1000,

$\sf \to Distance \: in \: km = 1.232 \: m$

• Converting the time in h.

We know that -

$\sf \to Time = 12 \: min$

We also know that -

$\sf \to 1 \: h = 60 \: min$

So we will -

$\sf \to Time \: in \: h = \dfrac{12}{60}$

Divide 12 by 60,

$\sf \to Time \: in \: h = 0.2 \: h$

• Finding the speed of the man.

We know that -

$\sf \to Speed = \dfrac{Distance}{Time}$

Substitute the values,

$\sf \to Speed = \dfrac{1.232 \: km}{0.2 \: h}$

Divide 1.232 by 0.2,

$\sf \to Speed = 6.16 \: km/h$

Final Answer:

∴ Thus, the distance covered by the man is 6.61 km/h.