Question

twenty seven solid iron spheres ,each of radius 2cm are melted to form a sphere . what will be the surface area of the new sphere

Answer 1

Answer:

452.57cm^2 (approx)

Step-by-step explanation:

volume of smaller sphere= 4/3(pie)r^3

total volume of cubes = 27*4/3(pie)r^3

total volume of spheres = volume of larger sphere

this gives radius of larger sphere = 6cm

surface area= 4(pie)r^2 = 452.57cm^2 (appro)

Answer 2

The surface area of the new sphere is 452.16 sq.cm.

Given:

27 small sphere of radius 2 cm converted to a new sphere.

To Find:

Surface area of the new sphere

Solution:

Let R be the radius of the new sphere.

when small 27 spheres are converted to a big sphere then volume must be same

$27\pi \frac{4}{3} 2^{3}=\pi \frac{4}{3}R^{3}\\ 27*2^{3}=R^{3}\\ R = 6cm$

Surface area of new sphere = 4πR² = 4×3.14×36

                                               = 452.16 sq.cm

Hence, the surface area of the new sphere is 452.16 sq.cm

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