A lead pencil consists of a cylinder of wood | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) Given that,$10 \,mm = 1 \,cm$,so $1 \,mm = 0.1 \,cm$.For the graphite cylinder:Diameter $= 1 \,mm = 0.1 \,cm$.Radius $(r) = \frac{0.1}{2} \,cm = 0

Vedclass · Accepted Answer

$5.28$

Vedclass · Answer

(D) Given that,$10 \,mm = 1 \,cm$,so $1 \,mm = 0.1 \,cm$.For the graphite cylinder:Diameter $= 1 \,mm = 0.1 \,cm$.Radius $(r) = \frac{0.1}{2} \,cm = 0.05 \,cm$.Length $(h) = 14 \,cm$.Volume of graphite $= \pi r^2 h = \frac{22}{7} 	imes (0.05)^2 	imes 14 \,cm^3 = 22 	imes 0.0025 	imes 2 \,cm^3 = 0.11 \,cm^3$.For the pencil:Diameter $= 7 \,mm = 0.7 \,cm$.Radius $(R) = \frac{0.7}{2} \,cm = 0.35 \,cm$.Length $(h) = 14 \,cm$.Volume of pencil $= \pi R^2 h = \frac{22}{7} 	imes (0.35)^2 	imes 14 \,cm^3 = 22 	imes 0.1225 	imes 2 \,cm^3 = 5.39 \,cm^3$.Volume of wood = Volume of pencil - Volume of graphite$= 5.39 \,cm^3 - 0.11 \,cm^3 = 5.28 \,cm^3$.Thus,the volume of the graphite is $0.11 \,cm^3$ and the volume of the wood is $5.28 \,cm^3$.

$A$ lead pencil consists of a cylinder of wood with a solid cylinder of graphite filled in the interior. The diameter of the pencil is $7 \,mm$ and the diameter of the graphite is $1 \,mm$. If the length of the pencil is $14 \,cm$,find the volume of the wood and that of the graphite. (in $,cm^3$)

Similar Questions

The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the slant height of the cone. (in $, cm$)

Find the cost of digging a cuboidal pit $8 \, m$ long,$6 \, m$ broad,and $3 \, m$ deep at the rate of $Rs. 30$ per $m^3$.

The diameter of the moon is approximately one-fourth of the diameter of the earth. Find the ratio of their surface areas.

$A$ corn cob (see figure),shaped somewhat like a cone,has the radius of its broadest end as $2.1\, cm$ and length (height) as $20\, cm$. If each $1\, cm^2$ of the surface of the cob carries an average of four grains,find how many grains you would find on the entire cob.

The paint in a certain container is sufficient to paint an area equal to $9.375 \,m^2$. How many bricks of dimensions $22.5 \,cm \times 10 \,cm \times 7.5 \,cm$ can be painted out of this container?

Vedclass Test Series

Exam Paper Generator

Online Exam Module