Advertisements
Advertisements
प्रश्न
From a solid cylinder whose height is 15 cm and diameter 16 cm, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid. (Use π = 3.14)
उत्तर
We have,
Height of the cylinder = Height of the cone = h = 15 cm and
Radius of thecylinder = Radius of the cone `= r = 16/2 = 8 "cm" `
Also, the slant height of the cone, `l =sqrt("h"^2 + "r"^2)`
`=sqrt(15^2 + 8^2)`
`=sqrt(225+64)`
`=sqrt(289)`
= 17 cm,
Now,
Then total surface area of the remaining solid = CSA of the cone + CSA of the cone + Area of the base
=πrl+ 2πrh + πr2
= πr (l + 2h + r)
= 3.14 × 8× (17 + 2 × 15 + 8)
= 3.1× 8 × 55
= 1381.6 cm2
So, the total surface area of the remaining solid is 1381.6 cm2.
Disclaimer: The answer given in the textbook is incorrect. The same has been corrected above.
APPEARS IN
संबंधित प्रश्न
Due to heavy floods in a state, thousands were rendered homeless. 50 schools collectively offered to the state government to provide place and the canvas for 1500 tents to be fixed by the governments and decided to share the whole expenditure equally. The lower part of each tent is cylindrical of base radius 2.8 cm and height 3.5 m, with conical upper part of same base radius but of height 2.1 m. If the canvas used to make the tents costs Rs. 120 per sq. m, find the amount shared by each school to set up the tents. What value is generated by the above problem? (use `pi =22/7`)
Find the weight of a hollow sphere of metal having internal and external diameters as 20 cm and 22 cm, respectively if 1m3 of metal weighs 21g.
A right angled triangle with sides 3 cm and 4 cm is revolved around its hypotenuse. Find the volume of the double cone thus generated.
The radii of the ends of a bucket of height 24 cm are 15 cm and 5 cm. Find its capacity. (Take π = 22/7)
The diameters of two circular ends of the bucket are 44 cm and 24 cm . The height of the bucket is 35 cm . The capacity of the bucket is
No Question.
The total surface area of a cube is 864 cm2. Its volume is
The total surface area of a hemisphere of radius 7 cm is
The circumference of the front wheel of a cart is 3 m long and that of the back wheel is 4 m long. What is the distance travelled by the cart, when the front wheel makes five more revolutions than the rear wheel?
A cylindrical tank has a radius of 154 cm. It is filled with water to a height of 3 m. If water to a height of 4.5 m is poured into it, what will be the increase in the volume of water in kl?
