Ex 6.3, 6

Transcript

Ex 6.4, 6 A car has two wipers which do not overlap. Each wiper has a blade of length 28 cm and sweeps through an angle of 120^∘. Find the total area cleaned at each sweep of the blades. Given that Radius = r = 29 cm Sweeping angle = 𝜃 = 120° Total area cleaned by the two wipers = 2 × Area cleaned by one wiper = 2 × Area of sector with angle 120° = 2 × 𝜃/360× 𝜋𝑟2 = 2 × 𝟏𝟐𝟎/𝟑𝟔𝟎×𝟐𝟐/𝟕×〖𝟐𝟖〗^𝟐 = 2 × 1/3×22/7× 28 × 28 = 2 × 1/3×22/1× 4 × 28 = 𝟒𝟗𝟐𝟖/𝟑 = 1642.666 cm2