The density of material at the center of a neutron star is approximately $1.00 \times 10 ^ { 18 } \mathrm {~kg} / \mathrm { m } ^ { 3 }$ What is the mass of a cube of this material that is 1.76 microns on each side. (One micron is equal to $1.00 \times$ $\left. 10 ^ { - 6 } \mathrm {~m} . \right)$
A) 5.45 kg
B) 6.16 kg
C) 4.74 kg
D) 6.70 kg

Question

The density of material at the center of a neutron star is approximately $1.00 \times 10 ^ { 18 } \mathrm {~kg} / \mathrm { m } ^ { 3 }$ What is the mass of a cube of this material that is  1.76  microns on each side. (One micron is equal to $1.00 \times$ $\left. 10 ^ { - 6 } \mathrm {~m} . \right)$
A)  5.45 kg
B)  6.16 kg
C)  4.74 kg
D)  6.70 kg

Quizplus · Accepted Answer

The volume of the cube is:$$V = (1.76 	imes 10^{-6} 	ext{ m})^3 = 5.32 	imes 10^{-18} 	ext{ m}^3$$The mass of the cube is:$$m = ho V = (1.00 	imes 10^{18} 	ext{ kg/m}^3)(5.32 	imes 10^{-18} 	ext{ m}^3) = 5.32 	ext{ kg}$$The closest answer choice is 5.45 kg, so the correct answer is A.

The Density of Material at the Center of a Neutron 1.00×1018 kg/m31.00 \times 10 ^ { 18 } \mathrm {~kg} / \mathrm { m } ^ { 3 }1.00×1018 kg/m3

The Density of Material at the Center of a Neutron $1.00 \times 10 ^ { 18 } \mathrm {~kg} / \mathrm { m } ^ { 3 }$