Advertisements
Advertisements
Question
Find the radius of a sphere whose surface area is 154 cm2.
`["Assume "pi=22/7]`
Solution
Let the radius of the sphere be r.
Surface area of sphere = 154
∴ 4πr2 = 154 cm2
r2 = `((154xx7)/(4xx22))cm^2`
= `((7xx7)/(2xx2))cm^2`
r = `(7/2) cm` = 3.5 cm
Therefore, the radius of the sphere whose surface area is 154 cm2 is 3.5 cm.
APPEARS IN
RELATED QUESTIONS
Find the surface area of a sphere of radius 14 cm.
The surface area of a sphere is 5544 `cm^2`, find its diameter.
The volume of a sphere is 38808 cm3; find its diameter and the surface area.
How many balls each of radius 1 cm can be made by melting a bigger ball whose diameter is 8 cm?
A hollow sphere of internal and external diameter 4 cm and 8 cm respectively is melted into a cone of base diameter 8 cm. Find the height of the cone.
The diameter of a sphere is 6 cm. It is melted and drawn into a wire of diameter 0.2 cm. Find the length of the wire.
A cone and a hemisphere have equal bases and equal volumes the ratio of their heights is
How many lead balls of radii 1 cm each can be made from a sphere of 8 cm radius?
There is a ratio 1: 4 between the surface area of two spheres, find the ratio between their radius.
A manufacturing company prepares spherical ball bearings, each of radius 7 mm and mass 4 gm. These ball bearings are packed into boxes. Each box can have maximum of 2156 cm3 of ball bearings. Find the:
- maximum number of ball bearings that each box can have.
- mass of each box of ball bearings in kg.
(use π = `22/7`)
