Question

a rectangular strip 16cm x 3.5 cm is rotated about the longer side .find the volume and the surface area of the solid thus generated

Answer 1

answer is 56 cube hope it will help

Answer 2

Answer:

Surface Area = 68.25π cm²

Volume of the cylinder = 196π cm³

Step-by-step explanation:

Length of rectangle = 16 cm

Width of rectangle = 3.5 cm

If we rotate a rectangle about its longer side, then the solid thus generated is right circular cylinder with height as the length of rectangle and radius as the width of rectangle

⇒ Height of cylinder = 16 cm and Radius of cylinder = 3.5 cm

Surface Area of cylinder = πr( r + h )

⇒ Surface Area = π·3.5 ( 3.5 + 16 )

⇒ Surface Area = 3.5π × 19.5

⇒ Surface Area = 68.25π cm²

Volume of cylinder = π·r²·h

⇒ Volume of the cylinder = π· 3.5² × 16

⇒ Volume of the cylinder = 196π cm³