Question

49. The length of a minute hand of a wall
clock is 7 cm. The area swept by it in 15
minutes.​

Answer 1

Answer:

51.333 cm² = 154/3 cm^2

Step-by-step explanation:

Given Problem:

The length of a minute hand of a wall clock is 7 cm. The area swept by it in 15  minutes.​

Solution:

To Find:

The area swept by it in 15  minutes.​

-------------------------

Method:

We know that,

60 minutes = 1 revolution by minute hand.

So,

1 minute= 1/60 revolution.

20 minutes= 1/60 x 20=1/3 revolution.

We know,

1 revolution = 1 circle area  

1/3 revolution=1/3 circle area

Hence,

Area formed in 20 minutes by minute hand =1/3 πr^2

=1/3 x 22/7 x 7 x 7= 154/3 cm^2 = 51.333 cm²