A rocket is in the form of circular cylinder closed at the lowerend and a cone of the same radius is attached to the top. The radius de
8 m. Calculate the total surface area of the rocket,
12. Arocket is in the form of a circular cylinder closed at the lower end
cylinder is 2.5 m, its height is 21 m and the slant height of the cone is 8m . Calculate the total surface area of rocket
Answers
Radius of cone and cylinder (r) =2.5 m......
height of cylinder (h)= 21 m......
slant height of cone. (l) =8 m......
total surface area of rocket = C.S.A area of cone + C.S.A. area of cylinder + area of base.....
= πrl +2πrh +πr^2...
= πr ( l + 2h + r ) ...
= πr ( 8 + 2*21+ 2.5)....
= 22/7 * 2.5 * 52.5......
=55*7.5....
= 412.5 m^2......
hence, total surface area of rocket is 412.5 m^2......
hope its helpful to you ...
.......ANSWER
Cylinder
r= 6/2
=3cm
H=12cm
Cone
l=5cm
r=3cm
∴l
2
=r
2
+h
2
or h
2
=l
2
−r
2
=5
2
−3
2
=25−9=16
⇒h=
16
=4cm
Now, volume of rocket
= Volume of cylinder + Volume of cone
=πr
2
H+
3
1
πr
2
h=πr
2
[H+
3
1
h]
=3.15×3×3[12+
3
1
×4]
=3.14×9[
3
40
]=3.14×3×40=376.8cm
3
.
∴ Volume of Rocket = 376.8cm
3
Total surface area of rocket = Curved surface area of cylinder + Curved surface area of cone + Area of base of cylinder [As it is closed (Given)]
=2πrH+πrl+πr
2
=πr[2H+l+r]
=3.14×3[2×12+5+3]
=3.14×3×32
301.44cm
2
Hence, the surface area of the rocket is 301.44cm
2
.