Question

.
7. The inner diameter of a wooden cylindrical pipe is 24 cm and its outer diameter is 28 cm. The length of the
pipe is 35 cm. Find the mass of the pipe, if 1 cm of wood weighs 3g.​

Answer 1

Answer:

85.8 kg

Step-by-step explanation:

Given-----> Inner and outer diameter of cylinder is 24 Cm and 28 Cm and length of the pipe is 35Cm and mass of 1Cm³ of wood weighs 3gm.

To find----> Mass of the pipe .

Solution-----> ATQ,

Inner diameter of pipe = 24 Cm

Outer diameter of pipe = 28Cm

Inner radius of pipe = 12 Cm

Outer diameter of pipe = 14 Cm

Volume of pipe

= External volume - Internal volume

= π R² h - π r² h

= π h ( R² - r² )

= ( 22/7 ) × 35 × { ( 14 )² - ( 12 ) }

= 22 × 5 × ( 196 - 144 )

= 110 × 5 × 52

= 550 × 52

= 28600 Cm³

Weight of 1 Cm³ of wood = 3 gm

Weight of wooden pipe = 28600 × 3

= 85800 gm

= 85800 / 1000 kg

= 85.8 Kg

Answer 2

Given:

• The inner diameter of a wooden cylindrical pipe is 24 cm. Inner radius,r = 12 cm.

• The outer diameter of a wooden cylindrical pipe is 28 cm. Outer radius,R = 14 cm.

• The length of the pipe, h = 35 cm

• 1 cm³ of wood weights 3 g.

To find out:

Find the mass of the pipe.

Formula used:

Volume of the hollow cylinder = h ( R² - r² )

Solution:

Volume of the hollow cylinder = h ( R² - r² )

= 22/7 × 35 ( 14² - 12² )

= 22/7 × 35 ( 14 + 12 ) ( 14 - 12 )

= 22/7 × 35 × 26 × 2

= 22/7 × 35 × 52

= 5270 cm³

1 cm³ wood weights 3 g .

Mass of the wood in the pipe= 5720 × 3g

= 17160 g

= 17160/1000 kg

= 17.16 Kg