Advertisements
Advertisements
Question
There are two cones. The curved surface area of one is twice that of the other. The slant height of the later is twice that of the former. Find the ratio of their radii.
Solution
Let curved surface area off 1^st cone = 2x
CSA of 2^nd cone=x
`"and slant height of 1 ^st cone=h "`
`"and slant height of 2 ^nd cone = 2h"`
`"CSA of 1^st cone" / "CSA of 2^nd cone"=(2x)/x=2/1`
⇒ `(pir_1l_1)/(pir_2l_2)=2/1`
⇒ `r_1h/r_2h=2/1⇒r_1/r_2=4/1`
APPEARS IN
RELATED QUESTIONS
A joker’s cap is in the form of right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 10 such caps.
`["Assume "pi=22/7]`
Find the curved surface area of a cone with base radius 5.25 cm and slant height 10cm.
The volume of a right circular cone is 9856 cm3. If the diameter of the base is 28 cm, find:
(i) height of the cone (ii) slant height of the cone (iii) curved surface area of the cone.
A conical pit of top diameter 3.5 m is 12 m deep. What is its capacity in kilo litres?
The radius and the height of a right circular cone are in the ratio 5 : 12 and its volume is 2512 cubic cm. Find the radius and slant height of the cone. (Take π = 3.14)
A heap of wheat is in the form of a cone of diameter 16.8 m and height 3.5 m. Find its volume. How much cloth is required to just cover the heap?
A solid metallic cone, with radius 6 cm and height 10 cm, is made of some heavy metal A. In order to reduce its weight, a conical hole is made in the cone as shown and it is completely filled with a lighter metal B. The conical hole has a diameter of 6 cm and depth 4 cm. Calculate the ratio of the volume of metal A to the volume of the metal B in the solid.
A vessel is in the form of an inverted cone. Its height is 8 cm and the radius of its top, which is open, is 5 cm. It is filled with water up to the brim. When lead shots, each of which is a sphere of radius 0.5 cm, are dropped into the vessel, one-fourth of the water flows out. Find the number of lead shots dropped in the vessel.
A conical tent is accommodate to 11 persons each person must have 4 sq. metre of the space on the ground and 20 cubic metre of air to breath. Find the height of the cone.
The curved surface area of a right circular cone of height 15 cm and base diameter 16 cm is
