Question

a rocket is in the form of a circular cylinder closed at the lower end with the cone of the same base radius attach to the top the cylinder is of radius 2 5 m and height 21 m & the cone has slant height 8cm find the total surfce area of the volume of the rocket .

Answer 1

Solution:-

There is a mistake in this question. The slant height of the cone should be 8 m instead of 8 cm.

Curved surface area of cone = πrl
= 22/7*2.5*8
= 440/7
= 62.86 sq m
Curved surface area of cylinder = 2πrh
= 2*22/7*2.5*21
= 330 sq m
Area of the base circle of the cylinder = πr²
= 22/7*2.5*2.5
= 19.64 sq m
Total surface area of rocket = 62.85 + 330 + 19.64
= 412.5 sq m
Volume of cylinder = πr²h
= 22/7*2.5*2.5*21
= 412.5 cu m
Now 
h² = 8² - (2.5)²
h² = 64 - 6.25
h² = 57.75
h = √57.75
h = 7.6 m
Volume of the cone = 1/3πr²h
= 1/3*22/7*2.5*2.5*7.6
= 49.76 cu m
Total volume of rocket = 412.5 + 49.76
= 462.26 cu m
Answer.

Answer 2

hope my answer helps you
DIKSHA