Question

The d of a metallic ball is 4.2cm. What is the mass of the ball, if the density of he metal is 8.9g per cm^3.

Answer 1

Diameter=4.2cm.....
Therefore, Radius=2.1cm
Now, Vol. of the ball
$= \frac{4}{3} \pi {r}^{3} \\ = ( \frac{4}{3} \times \frac{22}{7} \times 2.1 \times 2.1 \times 2.1) \\ = 38.808 {cm}^{3}$
And, Density = 8.9g
So, Weight = Vol. × Density
$= (30.808 \times 8.9) \\ = 345.3912g$
THERE YOU GO!!!.....