Question

Surface
area
of football is 1oo pi sq metres.
Find the volume
of
air in it​

Answer 1

Answer:

Here, l = 1.5 m, b = 1.25 m                                  ∵ It is open from the top.                 ∵ Its surface area = [Lateral surface area] + [Base area]                 = [2(l + b)h] + [l × b]                 = [2(1.50 + 1.25)0.65 m2] + [1.50 × 1.25 m2]                 = [2 × 2.75 × 0.65 m2] + [1.875 m2]                 = 3.575 m2 + 1.875 m2 = 5.45 m2                 ∵ The total surface area of the box = 5.45 m2                 ∴ Area of the sheet required for making the box = 5.45 m2

Step-by-step explanation:

Answer 2

Answer:

Let r cm be the radius of the sphere. Its surface area =55.44cm2

⇒ 4πr2=55.44

⇒ 4×722×r2=55.44

⇒ r2=4×2255.44×7=4.41=(2.1)2

⇒ r=2.1cm

now, volume of the sphere=34πr3=31(4πr2)×r=31×55.44×2.1cm3

=55.55×0.7cm3

Hence the volume of the sphere =38.808cm3