In a SUPW class, 20 student made pen stand of cupboard. the base of the pen stand is a circle with radius 3.5 cm and height of the pen stand is 10.5 cm .find how much cupboard was used by each. how much glazed paper is used on its outer surface also find the total cupboard and glazed paper used by the whole class .
Answers
Cardboard was used by each student=
Glazed paper is used on its curved surface =
Total cardboard used by class=
Total glazed paper used by the class=
Step-by-step explanation:
Radius of base=r=3.5 cm
Height of pen stand=h=10.5 cm
Cardboard was used by each student=
?f=%24%242%5Cpi%20rh%2B%5Cpi%20r%5E2%3D%5Cpir(2h%2Br)%24%24
\pi=\frac{22}{7}
Substitute the values then we get
Cardboard was used by each student=
\frac{22}{7}\times 3.5(2\times 10.5+3.5)
Cardboard was used by each student=
269.5 cm^2
Glazed paper is used on its curved surface =
2\pi rh=2\times \frac{22}{7}\times 3.5\times 10.5=231cm^2
Glazed paper is used on its curved surface =
231cm^2
Total cardboard used by class=
20\times 269.5=5390cm^2
Total glazed paper used by the class=
231\times 20=4620cm^2
____________________________
No. of students in the SUPW class = 20
The radius of the base of the pen stand, r = 3.5 cm
The height of the pen stand, h = 10.5 cm
Thus,
Total cardboard required to make one pen stand is given by,
= [CSA of a cylinder] + [CSA of base of pen stand]
= [2πrh] + [πr²]
= πr [2h + r]
= (22/7) * 3.5 * [(2*10.5) + 3.5]
= (22/7) * 3.5 * 24.5
= 269.5 cm²
_________________________________________
Thus,
Glazed paper used on the outer curved surface of the pen stand (neglecting the base area) is given by,
= [Cardboard required to make one pen stand] – [Area of the base of the pen stand]
= 269.5 – [π²]
= 269.5 – [(22/7) * (3.5)²]
= 269.5 – 38.5
= 231 cm²
_______________________________________
= 20 * [(Total cardboard used for each pen stand) + (Total glazed paper used on the outer curved surface of each pen stand)]
= 20 * [269.5 + 231]
= 20 * 500.5
= 10010 cm²