the length of the minute hand of clock is 3.5cm.find the area awept by minute hand in 30 minutes....
Answers
Answer:
Area covered by the minute hand is 38.5 cm^2.
Step-by-step explanation:
Given,
Length of the minute hand of a clock is 3.5 cm.
On observing the condition, we can say if the minute hand revolves once, it will form an imaginary circle of radius 3.5 cm.
Here,
Minute hand revolves till it covers a distance in which it can complete 30 minute.
One complete rotation of a minute hand refers an hour( 60 minute ) and half rotation refers 30 minute.
It means : Minute hand of clock covers half of a circle { of radius 3.5 cm }.
From the properties of circle
- Area of circle = πr^2 , where r is the radius of the circle.
Here,
Radius of the circle is 3.5 cm.
Therefore,
= > Area covered by minute hand = π x 3
( 3.5 cm )^2
= > Area covered by minute hand = 22 / 7 x 3.5 x 3.5 cm^2
= > Area covered by minute hand = 38.5 cm^2 .
π { pi } is a constant, it has few values which are approximately equal. Values : 22 / 7 or 355 / 115 or 3.14.
Area covered by the minute hand is 38.5 cm^2.