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Asked by G Bhanuteja

Feb 27, 2014

# A semi circular sheet of metal of diameter 28 cm

Q. A semi circular sheet of metal of diameter 28 cm is bent into an open conical cup. Find the depth and capacity of cup.

#### question_answer Answers(2)

Answer

Syeda

Member since Jan 25, 2017

Answer. Given diameter = 28 cm Radius, r = 14 cm Circumference of semi circle = Ï€r = (22/7) x 14 = 44 cm This becomes circumference of base of cone 2Ï€R = 44 R = 44 x (7/44) R = 7 cm The radius of semi circular sheet = slant height of conical cup That is l = 7 cm We know that r2 + h2 = l2 142 + h2 = 72 196 â€“ 49 = h2 h2 = 147 Therefore, h = 7âˆš3 cm That is depth of the conical cup is 7Ã–3 cm Capacity of cup = (1/3) Ï€r2h                               = (1/3) x (22/7) x 72 x 7âˆš3                               = 622.37 cu cm

Kishore Kumar

Member since

depth and capacity of cup. Given diameter = 28 cm Radius, r = 14 cm Circumference of semi circle = Ï€r = (22/7) x 14 = 44 cm This becomes circumference of base of cone 2Ï€R = 44 R = 44 x (7/44) R = 7 cm The radius of semi circular sheet = slant height of conical cup That is l = 7 cm We know that r2 + h2 = l2 142 + h2 = 72 196 â€“ 49 = h2 h2 = 147 Therefore, h = 7âˆš3 cm That is depth of the conical cup is 7Ã–3 cm Capacity of cup = (1/3) Ï€r2h                               = (1/3) x (22/7) x 72 x 7âˆš3                               = 622.37 cu cm (nearly)
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