l Surface area.r are in the ratio 4:7 and its volume is 251b cm.Find i

1.	l Surface area.r are in the ratio 4:7 and its volume is 251b cm.Find its10. (a) Arectangular paper of width 14 cm is rolled along its width and a cylinder of radiuspaper20cm is formed. Find the volume of the cylinder. I76ĆĄĆĄ cm(b) A recgular piece of paper 11 cm x 4 cm is folded without overlapping to make acylinder of height 4 cm. Find the volume of the cylinder. 3 g , 5 cm 3EL III
Answer» Given : A rectangular paper of width 14 cm is rolled along its width to form a cylinder . So Height of cylinder =h = 14 cm = width of the rectangular paper AndRadius of cylinder ( Given ) =r =20 cm Andwe know Volume of cylinder =πr2h, So Volume of our given cylinder =227×20×20×14=22×20×20×2=17600cm² Length of rectangle paper =11cmBreath of rectangular paper =4cm So circumference of circular part of cylinder =2 pi r So it is equal to length of paper (paper folded in shape of cylinder) 7=2 pi rr=7/2 piR=1.11cm Volume of cylinder = pi r² hH=4cmR=1.11cm Volume = 3.14x(1.11)²x4=15.48cm ??

l Surface area.r are in the ratio 4:7 and its volume is 251b cm.Find its10. (a) Arectangular paper of width 14 cm is rolled along its width and a cylinder of radiuspaper20cm is formed. Find the volume of the cylinder. I76ĆĄĆĄ cm(b) A recgular piece of paper 11 cm x 4 cm is folded without overlapping to make acylinder of height 4 cm. Find the volume of the cylinder. 3 g , 5 cm 3EL III

Answer»

Given : A rectangular paper of width 14 cm is rolled along its width to form a cylinder . So

Height of cylinder =h = 14 cm = width of the rectangular paper

AndRadius of cylinder ( Given ) =r =20 cm

Andwe know Volume of cylinder =πr2h, So

Volume of our given cylinder =227×20×20×14=22×20×20×2=17600cm²

Length of rectangle paper =11cmBreath of rectangular paper =4cm

So circumference of circular part of cylinder =2 pi r

So it is equal to length of paper (paper folded in shape of cylinder)

7=2 pi rr=7/2 piR=1.11cm

Volume of cylinder = pi r² hH=4cmR=1.11cm

Volume = 3.14x(1.11)²x4=15.48cm