Question

a boy completes a sime circle of radius 7m in 5sec. the distance travelled by the boy is a) 7m
b) 10m
c)11m
d)22m​

Answer 1

Answer:

Option D (22 m)

Explanation:

As per the provided information in the given question, we have :

• A boy completes a semi-circle of radius 7m in 5 sec.

We are asked to calculate the distance travelled. $\;$

Let us say the body starts from point A, so after completing a semi-circle, it'll come to point B. Distance travelled is the total length of the path covered by the body. Its SI unit is metre and it is a scalar quantity.

So, we have to calculate the length of the total path from A to B.The length of the total path from A to B can also be considered as the perimeter of the semi-circle. Perimeter of the semi-circle is half of the circumference of the circle.

Le the distance here be "S".

↠S = Perimeter of the semi-circle

↠S = Circumference ÷ 2

↠S = 2πr ÷ 2

↠S = {2 × ²²/₇ × 7 m} ÷ 2

↠S = {2 × 22 m} ÷ 2

↠ S = 44 m ÷ 2

↠ S = 22 m

∴ The distance travelled is 22 m.