A Sphere Is Constructed of Two Concentric Parts

question 49

Essay

A sphere is constructed of two concentric parts.The inner part is a solid sphere of radius
10.0 cm made of a material with density 4000 kg/m³.The outer part is a spherical shell with inner radius 10.0 cm and outer radius 20.0 cm.The material in the outer shell has a density
9000 kg/m³.
(a)What is the mass of the sphere?
(b)What is the average density of this sphere?

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Definitions:

Id

In psychoanalytic theory, the part of the mind in which innate instinctive impulses and primary processes are manifest.

Id

In psychoanalytic theory, the part of the personality that contains our primal, instinctual drives and operates on the pleasure principle.

Ego

In psychoanalytic theory, the part of the personality that mediates between the demands of the id, superego, and reality.

Libido

A term used in psychoanalytic theory to denote the sexual drive or desire.