The volume of an object is equal to the ratio of its mass to its density, [tex]$V=\frac{m}{d}$[/tex]. The mass of a spherical grape is 8.4 grams and its density is 2 grams per cubic centimeter.

What is the radius of the grape? Round to the nearest tenth of a centimeter.

A. 1.0 cm
B. 1.5 cm
C. 1.9 cm
D. 2.1 cm



Answer :

To determine the radius of the spherical grape, we need to use the relationship between the mass, density, and volume, followed by applying the formula for the volume of a sphere. Here is the step-by-step solution:

1. Calculate the volume of the grape:
- The formula for volume (V) based on mass (m) and density (d) is given by:
[tex]\[ V = \frac{m}{d} \][/tex]
- Substitute the given values: mass [tex]\( m = 8.4 \)[/tex] grams and density [tex]\( d = 2 \)[/tex] grams per cubic centimeter:
[tex]\[ V = \frac{8.4}{2} = 4.2 \text{ cubic centimeters} \][/tex]

2. Relate the volume of the grape to the volume of a sphere:
- The formula for the volume of a sphere is:
[tex]\[ V = \frac{4}{3} \pi r^3 \][/tex]
- To find the radius [tex]\( r \)[/tex], solve for [tex]\( r^3 \)[/tex]:
[tex]\[ r^3 = \frac{3V}{4\pi} \][/tex]

3. Substitute the volume into the equation:
- Using [tex]\( V = 4.2 \)[/tex] cubic centimeters:
[tex]\[ r^3 = \frac{3 \times 4.2}{4\pi} \approx \frac{12.6}{12.566370614359172} \approx 1.0026761414789407 \][/tex]

4. Calculate the radius by taking the cube root of [tex]\( r^3 \)[/tex]:
- To find [tex]\( r \)[/tex], take the cube root of [tex]\( r^3 \)[/tex]:
[tex]\[ r = (1.0026761414789407)^{\frac{1}{3}} \approx 1.00089125259248 \text{ centimeters} \][/tex]

5. Round the radius to the nearest tenth:
- The radius is approximately [tex]\( 1.00089125259248 \)[/tex] centimeters.
- Rounding this value to the nearest tenth:
[tex]\[ r \approx 1.0 \text{ centimeters} \][/tex]

Thus, the radius of the grape is [tex]\( 1.0 \)[/tex] cm when rounded to the nearest tenth of a centimeter.