The Center of Mass of a System of Particles Has

question 95

Multiple Choice

The center of mass of a system of particles has a constant velocity if:

• A)the forces exerted by the particles on each other sum to zero
• B)the external forces acting on particles of the system sum to zero
• C)the velocity of the center of mass is initially zero
• D)the particles are distributed symmetrically around the center of mass
• E)the center of mass is at the geometric center of the system

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Definitions:

Cyclic AMP

A secondary messenger important in many biological processes, such as the regulation of metabolism.

Lipid-soluble Hormones

Hormones that can easily cross cell membranes to enter cells due to their solubility in lipids.

Nuclear Receptor Model

A framework for understanding how certain receptor proteins within cell nuclei mediate the effects of lipophilic hormones, vitamins, and other ligands.

Receptor Molecule

A protein on the surface of a cell that binds to specific molecules, triggering a response in the cell.