Question

The minute hand of a clock is √21 𝑐𝑚 long. Find area described by the minute hand on the face of clock between 7 am and 7:05 am

Answer 1

Radius of minute hand (r) = √21 𝑐𝑚

For 1hr = 60 min, minute hand completes one revolution = 360°

60 min = 360°

1 min = 6°

From 7 am to 7:05 am it is 5 min angle subtended = 5 × 6° = 30° = 𝜃

Area described =`theta/360^@ × pir^2`

=`30/360×22/7`× 21

=`22/4`= 5.5 cm²