A Boy Wishes to Cross a River in the Shortest $\theta$

question 55

Multiple Choice

A boy wishes to cross a river in the shortest possible time, without necessarily landing directly across from his starting point.He can row at 2 m/s in still water and the river is flowing at 1 m/s.At what angle $\theta$ should he point the bow (front) of his boat?

• A)30 °
• B)45 °
• C)60 °
• D)63 °
• E)90 °

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Definitions:

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.

DNA

Deoxyribonucleic acid, a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.