A cylinder has a radius of 6 cm and a height of 15 cm. A hole of the shape of a cone is bored into one of its ends. If the cone has a radius of 3 cm, find the volume of the remaining solid.
Answers
Answer:
Given Diameter of cylinder = 7 cm So
Radius of solid cylinder = 3.5 cm
Height of cylinder = 15 cm
And
Radius of cone = 3 cm
Height of cone = 4 cm
So ,
Surface area of remaining solid cylinder = Total surface area of cylinder - Area of base of cones + curved surface area of cones
We know
Total surface area of cylinder = 2πr ( r + h ) , So
Total surface area of this solid cylinder = 2× 227 × 3.5 ( 3.5 + 15) ( As we know π = 227 )
Total surface area of this solid cylinder = 22 × 18.5 = 407 cm2
And
Area of base of cone = πr2 , So
Area of base of both cones = 2×πr2
Area of base of both cones = 2×227 × 3 × 3
Area of base of both cones = 3967 = 56.57 cm2
And
Slant height of cone l = h2 + r2−−−−−−−√ = 42 + 32−−−−−−−√ = 16 + 9−−−−−−√ = 25−−√ = 5 cm
we know curved surface area of cone = πrl , So
Curved surface area of both cones = 2 × πrl
Curved surface area of both cones = 2 × 227 × 3 × 5
Curved surface area of both cones = 6607 = 94.28 cm2
Then
Surface area of remaining solid cylinder = 407 cm2 - 56.57 cm2 + 94.28 cm2 = 444.71 cm2
1560 cm^3 is the correct answer.