Question

The minute hand of a clock is root 21 cm long find the area described by the minute hand on the face of the clock between 7:00 AM and 7:05 PM

Answer 1

1. the minute hand of a clock is √21 cm long. find the area described by the minute hand on the face of the clock between 7.00 am and 7.05 am.2. a playground is in the form of a rectangle having semicircles on the shorter sides. find it's area when the length of the rectangular portion is 80 m and the breadth is 42mGiven length of minute hand of a clock, 

We have to find the area described by the minute hand between 7:00 am and 7:05 am

That is we have to find area described by the minute hand in 5 minutes.

Recall that in 1 minute angle covered by the minute hand is 

Angle covered in 5 minutes 

We know that area of sector 

 

 

 sq cm

Hence area described by the minutes hand in 5 minutes is 115.5 sq cm.     

Answer 2

Answer:

5.5 cm²

Step-by-step explanation:

∅=360°/12          [12 no.s of the clock]

 =30°

∴ ar. covered by minute hand = ∅/360° ×π×r²

                                                 = 30°/360° ×22/7×√21×√21

                                                 =1/12 ×22×3

                                                 =11/2 =5.5 cm²