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The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm3?
The diameter of the metallic ball = 4.2 cm
The density of the metal = 8.9 g per cm3.
We know that,
Density = Mass / Volume
Volume of a sphere = 4/3πr3
Diameter of the metallic ball, d = 4.2cm
Radius of the metallic ball, r = 4.2/2cm = 2.1cm
The volume of the metallic ball = 4/3πr3
= 4/3 × 22/7 × 2.1cm × 2.1cm × 2.1cm
= 38.808 cm³
Now, Mass = Volume × Density
Mass of the metallic ball = 38.808 cm3 × 8.9g / cm³
= 345.3912 g
= 345.39 g (approx.)
Thus, the mass of the ball is 345.39 g.
The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm³?
NCERT Solutions for Class 9 Maths - Chapter 13 Exercise 13.8 Question 3
It is given that the diameter of a metallic ball is 4.2 cm. If the density of the metal is 8.9 g per cm³, we have found that the mass of the ball is 345.39 g.
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