Question

A car has two wipers which do not overlap. Each wiper has a blade of length 24 cm sweeping through an angle of 120º. Find the total area cleaned at each sweep of the blades.

(a) 192 π cm²

(b) 224 π cm² 

(c) 384 π cm² 

(d) 240 π cm²

Answer 1

Answer : (c) 384 π cm²

Total area cleaned at each sweep of the blades 

= 2 × Area of sector cleaned by the sweep of one blade

= 2 × \(\big[\) \(\frac{120}{360}\times \pi \times (24)^2 \big]\) \(\big[\because radius\,of\,sector\,=\,length\,of\,blade\big]\)

 = 384 π cm².