Advertisements
Advertisements
Question
A toy is in the form of a cone mounted on a hemisphere of common base radius 7 cm. The total height of the toy is 31 cm. Find the total surface area of the toy.
Solution
Radius of the hemisphere = Radius of the cone = 7 cm
Height of the cone = (31 - 7)cm = 24 cm
Slant height of the cone , `l =sqrt("r"^2 + "h"^2)`
`= sqrt((7)^2 + (24)^2)`
`=sqrt(49+576)`
`=sqrt(625)`
= 25 cm
Total surface area of the toy = (Curved surface area of the hemisphere) + (Curved surface area of the cone)
=2πr2 + πrl
= π × r × (2r + l)
`=22/7xx7xx(14+25) "cm"^2`
= 858 cm2
APPEARS IN
RELATED QUESTIONS
In a hospital used water is collected in a cylindrical tank of diameter 2 m and height 5 m. After recycling, this water is used to irrigate a park of hospital whose length is 25 m and breadth is 20 m. If tank is filled completely then what will be the height of standing water used for irrigating the park. Write your views on recycling of water.
Find the volume of a sphere of diameter 6 cm.
The vertical height of a conical tent is 42 dm and the diameter of its base is 5.4 m. Find the number of persons it can accommodate if each person is to be allowed 29.16 cubic dm.
A toy is in the form of a cone of radius 3.5 cm mounted on a hemisphere of same radius. The total height of the toy is 15.5 cm. Find the total
surface area of the toy.
The slant height of a bucket is 45 cm and the radii of its top and bottom are 28 cm and 7 cm, respectively. The curved surface area of the bucket is
The diameter of the base of a cylinder is 4 cm and its height is 14 cm. The volume of the cylinder is
Find the number of solid spheres, each of diameter 6 cm, that could be moulded to form a solid metallic cylinder of height 45 cm and diameter 4 cm.
A metal cuboid of measures 16 cm × 11 cm × 10 cm was melted to make coins. How many coins were made, if the thickness and diameter of each coin was 2 mm and 2 cm respectively? (π = 3.14)
A boy is cycling such that the wheels of the cycle are making 140 revolutions per hour. If the diameter of the wheel is 60 cm, calculate the speed in km/h with which the boy is cycling.
The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15 m respectively. 8400 L of water is pumped out from the reservoir. Find the fall in the water level in the reservoir.
