Question

Volume of a hollow sphere is 11352/7cm3. If outer radius is 8cm find inner radius of the sphere

Answer 1

Step-by-step explanation:

the answer is given in the attachment

Answer 2

The inner radius of the sphere is 5 cm

Step-by-step explanation:

• Given data

        Volume of hollow sphere (V) $\mathbf{=\frac{11352}{7} \ cm^{3}}$

        Outer radius of hollow sphere (R) = 8 cm

        Inner radius of hollow sphere (r) = Unknown

• We know formula of volume of hollow sphere, which are given below

        $\mathbf{Volume \ of \ hollow \ sphere(V)=\frac{4}{3}\times \frac{22}{7}\times (R^{3}-r^{3})}$

        $\mathbf{\frac{11352}{7}=\frac{4}{3}\times \frac{22}{7}\times (R^{3}-r^{3})}$

        $\mathbf{\frac{11352\times 3}{4\times 22}=(8^{3}-r^{3})}$

• On solving L.H.S of above equation

        387 = 8³ -r³

        r³ = 512 - 387

        r³ =125

        r³ = 5³

• So

        r = 5 cm = This will be inner radius of hollow sphere