Density (D) is described as the mass (m) of a material contained within a given volume (V). Mathematically, it is represented by:
Density = Mass ÷ Volume
D = m / V -------- (1)
Units: grams per cubic centimeter (g/cm³)
a)
Let m1, V1, and D1 denote the mass, volume, and density of ball A respectively, and m2, V2, and D2 represent mass, volume, and density of ball B.
Given: V1 = V2, and m1 = 2 × m2
Using equation (1):
D1/D2 = (m1/V1) ÷ (m2/V2) = (2m2/V2) ÷ (m2/V2) = 2
This implies ball A's density is twice that of ball B.
Answer: Ball A has the higher density.
b)
Let m1, V1, D1 be the mass, volume, and density of ball C, while m2, V2, D2 correspond to ball D.
Given: V1 = 3 × V2 and m2 = (1/3) × m1 → m1 = 3 × m2
Calculating:
D1/D2 = (m1/V1) ÷ (m2/V2) = (3m2/3V2) ÷ (m2/V2) = 1
Therefore, densities are equal.
Answer: Both have equal densities.
c)
Let m1, V1, D1 be the mass, volume, and density of ball P, and m2, V2, D2 for ball Q.
Given: m1 = m2, V1 = 2 × V2
Thus:
D1/D2 = (m1/V1) ÷ (m2/V2) = (m2/2V2) ÷ (m2/V2) = 1/2
So, ball P's density is half that of ball Q.
Answer: Ball Q has the greater density.
d)
Let m1, V1, D1 be the mass, volume, and density of ball X and m2, V2, D2 be the same for ball Y.
Given: V1 = 2 × V2 and m1 = (1/2) × m2
Then:
D1/D2 = (m1/V1) ÷ (m2/V2) = ((1/2) m2 / 2V2) ÷ (m2/V2) = 1/4
This means ball X’s density is one-fourth that of ball Y.
Answer: Ball Y has a higher density.