Question

The inner and outer radiiof the Hollow cylinder are 15cm and 20cm respectively.the cylinder is melted and recast into solid cylinder of thw same length.find the radius of the base of the new cylinder

Answer 1

The inner radius of hollow cylinder is r₁ = 15cm

And the outer radius is r₂ = 20 cm

SO the volume will be

= π(r₂² -r₁²) h

We know that the cylinder is melted and when we change it into a solid cylinder with the same height.

Now the radius of the solid cylinder will be r

The volume of solid cylinder = volume of hollow cylinder

r² = (20²  - 15²)

r² = 35 x 5

r = 13.2 cm

So the radius of the solid cylinder would be 13.2 cm

Answer 2

Answer:

The radius of the base of the new cylinder (solid cylinder) is 13.2 cm.

Step-by-step explanation:

SOLUTION :  

Let the radius of the solid cylinder be r1.

Given :  

Inner radius of hollow cylinder , r = 15 cm

Outer radius of hollow cylinder, R = 20 cm

Given : The hollow cylinder is melted into a solid cylinder with the same height.

Volume of solid cylinder = Volume of hollow cylinder

πr1² h = π(R² -r²) h

r1² = (R² -r²)  

r1² = (20²  - 15²)

r1² = 400 - 225 = 175 cm

r1 = √175

r1 = 13.2 cm

Hence, the radius of the base of the new cylinder (solid cylinder) is 13.2 cm.

HOPE THIS ANSWER WILL HELP YOU….