Wiper question A 42 cm long windshield wiper covers a quadrant and it sweeps across the glass If - Maths - Mensuration

Question

Wiper question

A 42 cm long windshield wiper covers a quadrant and it sweeps
across the glass If the outer 35 cm of the wiper is fitted with
scrubber, then the area of the glass wiped clean by the wiper in
one sweep will be

Shruti Tyagi · Accepted Answer

Dear Student,

it is given that the wiper covers a quadrant of the glass
Area of quadrant=14×πr2Now the length of wiper=42 cm but only the outer 35 cm contains scrubber the remaining 42-35= 7 cm will not be able to clean the galssHence the area of glass cleaned by wiper=Area of glass cleaned by full wiper -area of glass cleaned by 7 cm=14×π422-14×π72=14×227×422-14×227×72=22×6×424-22×74=55444-1544=53904=1347
5 cm2

Regards,

Wiper question A 42 cm long windshield wiper covers a quadrant and it sweeps across the glass. If the outer 35 cm of the wiper is fitted with scrubber, then the area of the glass wiped clean by the wiper in one sweep will be

Wiper question

A 42 cm long windshield wiper covers a quadrant and it sweeps across the glass. If the outer 35 cm of the wiper is fitted with scrubber, then the area of the glass wiped clean by the wiper in one sweep will be