Question

a company packages its milk powder in a cylindrical container whose base has a diameter of 16.8 cm and height 20.5 cm. company places a label around a curved surface of the container. if the label is placed 1.5 cm from top and bottom, what is the surface area of the label

Answer 1

diameter=16.8cm

radius=8.4cm

height of the label=20.5-(1.5+1.5)

=20.5-3

=17.5

CSA=2πrh

=2×22/7×8.4×17.5

=44/7×147

=44×21

=924cm²

hope this helps u frnd....

Answer 2

Given,

Diameter of a cylinder (d) = 16.8 cm

Height of a cylinder (h) = 20.5 cm

To find,

The surface area of the label

Solution,

As the diameter of a cylinder d is 16.8 cm,

     Radius(r) = d/2

     Radius(r) = 16.8/2

     Radius(r) = 8.4 cm

Now, it is said that the label is placed 1.5 cm from top and bottom,

Height of the label  ($h_{L}$) is given by,

     $h_{L} = 20.5 - 1.5- 1.5$

     $h_{L} = 17.5 cm$

Therefore, the height of the label is 16.5 cm.

We know the formula for curved surface area is    

     A = 2 × $\pi$ × r × $h_{L}$

Substituting the values, we get

    A = 2 × 3.14 × 8.4 × 17.5            (Take the value of $\pi$ as 3.14)

    A = 923.16 $cm^{2}$

The surface area of the label is 923.16 cm2.