A spherical ball of lead has a diameter of 5.0 cm . What is the mass of the sphere if lead has a density of 11.34 g/em'? (The volume of a sphere is r" where r is t Express your answer using two significant figures.

1 answer

To find the mass of the spherical ball of lead, we can use the formula:

\[ \text{Mass} = \text{Density} \times \text{Volume} \]

First, we need to calculate the volume of the sphere. The formula for the volume \( V \) of a sphere is:

\[ V = \frac{4}{3} \pi r^3 \]

Given that the diameter of the sphere is 5.0 cm, we can find the radius \( r \):

\[ r = \frac{\text{diameter}}{2} = \frac{5.0 , \text{cm}}{2} = 2.5 , \text{cm} \]

Now, we can calculate the volume:

\[ V = \frac{4}{3} \pi (2.5 , \text{cm})^3 \]

Calculating \( (2.5 , \text{cm})^3 \):

\[ (2.5)^3 = 15.625 , \text{cm}^3 \]

Now substituting back into the volume formula:

\[ V = \frac{4}{3} \pi (15.625 , \text{cm}^3) \]

Using \( \pi \approx 3.14159 \):

\[ V \approx \frac{4}{3} \times 3.14159 \times 15.625 \approx 65.45 , \text{cm}^3 \]

Next, we will calculate the mass using the density of lead, which is given as 11.34 g/cm³:

\[ \text{Mass} = \text{Density} \times \text{Volume} = 11.34 , \text{g/cm}^3 \times 65.45 , \text{cm}^3 \]

Calculating the mass:

\[ \text{Mass} \approx 11.34 \times 65.45 \approx 742.78 , \text{g} \]

Finally, rounding this to two significant figures, we get:

\[ \text{Mass} \approx 740 , \text{g} \]

Therefore, the mass of the sphere is approximately 740 g.