Math, asked by gillkashmir46, 1 month ago

Q.37 There is a cylinder of height 30 cm and its radius is 14 cm. It is melted to form a new
cylinder of radius 7 cm. The height of the new cylinder is

Answers

Answered by fahims8080
1

as volume of  first cylinder=v1=v2

let  use the formula of volume of cylinder

v=\pi r^{2} h

putting value

v=22/7 x14^{2} x 30

v=3.14 x196 x30

v=18463.2

as v1=v2

now

new cylinder

v=\pi r^{2} h

18463.2=22/7 x7 xh

h= 18463.2/ 22

h=839.236

hence height of new cylinder is=839.236

Answered by GulabLachman
0

Given: There is a cylinder of height 30 cm and its radius is 14 cm. It is melted to form a new cylinder of radius 7 cm.

To find: Height of the new cylinder

Explanation: Let the radius and height of the first cylinder be r1 and h1 respectively.

r1=14 cm

h1= 30 cm

Volume of first cylinder

 = \pi \times  {r1}^{2}  \times h1

 = 3.14 \times  {14}^{2}  \times 30

 = 3.14 \times 196 \times 30

 = 18463.2 {cm}^{2}

Since this cylinder is melted to form a new cylinder, the volume occupied by both the cylinders are same.

Therefore, volume of new cylinder= 18463.2

Let the radius and height of the new cylinder be r2 and h2 respectively.

r2= 7 cm

Volume of second cylinder

 = \pi \times  {r2}^{2}  \times h2

 = 3.14 \times  {7}^{2}  \times h2

 = 153.86 \times h2

Therefore,

153.86 × h2 = 18463.2

=> h2 = 120 cm

Therefore, height of the new cylinder is 120 cm.

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