Question

2. A spherical metallic shell with 10 cm external
diameter weighs 1789 g. Find the thickness of the
3
shell if the density of metal is 7 g/cm?.
​

Answer 1

Answer:

Mass of the spherical metallic shell = 1789 1/3 g

= 5368/3 g

Density = 7 g/cm³  

Volume of the spherical metallic shell = Mass/density

⇒ 5368/7 ÷ 7

= 255.61 cm³

Now,

External diameter = 10 cm

So, external radius = 5 cm

Let the internal radius be 'r'

Now,

According to the question.

4/3π(R³ - r³) = 255.61 cm³

⇒ 5³ - r³ = (255.61*3)/(4*3.14)

⇒ 125 - r³ = 766.83/12.56

⇒ 125 - r³ = 61.05

⇒ r³ = 125 - 61.05

⇒ r³ = 63.95

⇒ r = ∛63.95

⇒ r = 3.9989 or 4 (Approx)

So, the thickness = 5 - 4  

= 1 cm

Answer.

Step-by-step explanation:

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Answer 2

Answer:

d=10cm

So, external r= d/2= 5 cm (Let external radius= ro)

Let internal radius= ri

Weight=  g= 5368g

Density (D)= 7g/cm³

Volume of the sphere= Outer vol- Inner vol  

=  

Let this be V

Therefore, for 1cm³ of Vol., weight= 7g

So for V cm³, wt =7*V g

=

g

But, given wt = 5368 g

So,  

or,  

Now, thickness= 1.13 cm

Step-by-step explanation:

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