Advertisements
Advertisements
प्रश्न
An iron pillar consists of a cylindrical portion 2.8 m high and 20 cm in diameter and a cone 42 cm high is surmounting it. Find the weight of the pillar, given that 1 cubic cm of iron weighs 7.5 gm.
उत्तर
Volume of cylindrical portion
`=pir^2h`
`= 22/7 xx (20/2)^2 xx 280`
`= 88000 cm^3`
Volume of conical portion
`=1/3pir^2h`
` =1/3 xx 22/7 xx (10)^2 xx 42`
`=4400 cm^3`
Total number
`= 8800 + 4400`
`=92400`
So total height
`=92400 xx 7.5`
`= 693000 gm`
`= 693 kg`
APPEARS IN
संबंधित प्रश्न
Water is flowing at the rate of 2.52 km/h through a cylindrical pipe into a cylindrical tank, the radius of whose base is 40 cm. If the increase in the level of water in the tank, in half an hour is 3.15 m, find the internal diameter of the pipe.
A spherical ball of iron has been melted and made into smaller balls. If the radius of each smaller ball is one-fourth of the radius of the original one, how many such balls can be made?
A solid metallic spherical ball of diameter 6 cm is melted and recast into a cone with diameter of the base as 12 cm. The height of the cone is
A river 1.5 m deep and 36 m wide is flowing at the rate of 3.5 km/hr. Find the amount of water (in cubic metres) that runs into the sea per minute.
The ratio between the volume of two spheres is 8 : 27. What is the ratio between their surface areas?
The total surface area of a hemisphere of radius 7 cm is
The radii of the top and bottom of a bucket of slant height 45 cm are 28 cm and 7 cm, respectively. Find the curved surface area of the bucket.
How many solid cylinders of radius 6 cm and height 12 cm can be made by melting a solid sphere of radius 18 cm?
Activity: Radius of the sphere, r = 18 cm
For cylinder, radius R = 6 cm, height H = 12 cm
∴ Number of cylinders can be made =`"Volume of the sphere"/square`
`= (4/3 pir^3)/square`
`= (4/3 xx 18 xx 18 xx 18)/square`
= `square`
______ of a solid is the measurement of the space occupied by it.
The radius of a metallic sphere is 8 cm. It was melted to make a wire of diameter 6 mm. Find the length of the wire.
