Question

1
select the correct text.
a spherical ball for a machine was made with a radius of 2 centimeters.
if the ball has a mass of 278.1 grams, which material was used to make the ball?
copper – 8.3 g/cm³ brass – 8.6 g/cm³ iron – 7.8 g/cm³

Explanation:

Step1: Calculate the volume of the sphere

The formula for the volume of a sphere is $V = \frac{4}{3}\pi r^3$. Given $r = 2$ cm, we substitute:
$V=\frac{4}{3}\pi(2)^3=\frac{4}{3}\pi\times8=\frac{32\pi}{3}\approx\frac{32\times3.14}{3}\approx33.49$ $cm^3$

Step2: Calculate the density of the material

Density $
ho=\frac{m}{V}$, where $m = 278.1$ g and $V\approx33.49$ $cm^3$.
$
ho=\frac{278.1}{33.49}\approx8.3$ $g/cm^3$

Step3: Identify the material

The density $8.3$ $g/cm^3$ matches the density of copper.

Answer:

Copper (since the calculated density is approximately $8.3$ $g/cm^3$ which corresponds to copper's density)