A solid cylinder is of height 15 cm and diameter 7 cm. Two equal conical holes of radius 3 cm and height 4 cm are cut off, one from each circular end. find the surface area of the remaining solid
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HELLO DEAR,
Given:-
Height of the cylinder (H) = 14 cm
Diameter of the base of cylinder = 7 cm
radius of the base of cylinder (R)= 7/2 cm
Surface area of cylinder = 2πR(R+H)
=> 2x (22/7)x(7/2)(7/2 + 14)
=> 2 x 11x (35/2)
=> 385 cm2
Now Radius of base of cone (r) = 3 cm
height of cone (h) = 4 cm
Surface area of cone = πr(r + √(h2 + r2))
=> (22/7)x3x(3 + √(42 + 32) )
=> (22/7)x3x(3 + 5)
=> (22x3x8)/ 7
=> 528 / 7
=> 75.43 cm2
Hence the surface area of the remaining
solid
= >Surface area of cylinder
– Surface area of 2 cones
=> 385 cm2 – 2x75.43 cm2
=> 385 cm2 – 150.86 cm2
=> 234.14 cm2
I HOPE ITS HELP YOU DEAR,
THANKS
Given:-
Height of the cylinder (H) = 14 cm
Diameter of the base of cylinder = 7 cm
radius of the base of cylinder (R)= 7/2 cm
Surface area of cylinder = 2πR(R+H)
=> 2x (22/7)x(7/2)(7/2 + 14)
=> 2 x 11x (35/2)
=> 385 cm2
Now Radius of base of cone (r) = 3 cm
height of cone (h) = 4 cm
Surface area of cone = πr(r + √(h2 + r2))
=> (22/7)x3x(3 + √(42 + 32) )
=> (22/7)x3x(3 + 5)
=> (22x3x8)/ 7
=> 528 / 7
=> 75.43 cm2
Hence the surface area of the remaining
solid
= >Surface area of cylinder
– Surface area of 2 cones
=> 385 cm2 – 2x75.43 cm2
=> 385 cm2 – 150.86 cm2
=> 234.14 cm2
I HOPE ITS HELP YOU DEAR,
THANKS
rohitkumargupta:
ya
its ok
red wale pe thnx bolo
If there would be any I will ask you
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but
me
no here
solid=ar. of cylinder+ar. of cone
diameter of cylinder=7cm
radius=7/2cm
radius of conical hole=3cm
height=4cm
so l=h^2+r^2(hole root)
l=(4)^2+(3)^2(hole root)
l=16+9(hole root)
l=25(hole root)
root of 25 is 5 so,
l=5cm
put it in formula,
2*22/7*7/2*15+2(22/7*3*5) (because there are two conical holes)
330+2(22/7*3*5)
330+2(330/7)
330+660/7
2310+660/7
2970/7cm^2
diameter of cylinder=7cm
radius=7/2cm
radius of conical hole=3cm
height=4cm
so l=h^2+r^2(hole root)
l=(4)^2+(3)^2(hole root)
l=16+9(hole root)
l=25(hole root)
root of 25 is 5 so,
l=5cm
put it in formula,
2*22/7*7/2*15+2(22/7*3*5) (because there are two conical holes)
330+2(22/7*3*5)
330+2(330/7)
330+660/7
2310+660/7
2970/7cm^2
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I hope this is correct answer..............
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