A Uniform Wire Is Bent into a Semi-Circle of Radius $\pi$

question 19

Multiple Choice

A uniform wire is bent into a semi-circle of radius R and laid out such that it is entirely in the x-y plane .The semicircle has its ends fixed on the x axis at x = -R and x = +R.With the exception of its end points,the semicircle is entirely above the x-axis (i.e.the y-coordinates of all points on its arc are positive) .What is the y coordinate of its center-of-mass?

• A)2R/\(\pi\)
• B)R/3
• C)R/2
• D)2R
• E)R/ 

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Definitions:

Erosion

The process by which natural forces remove soil, rock, or dissolved material from one location and transport it to another.

Phytoremediation

The use of plants to remove, detoxify, or immobilize environmental contaminants in soil or water through natural processes.

Translocation

In genetics, structural rearrangement in which a broken piece of chromosome has become reattached in the wrong location. In plants, movement of organic compounds through phloem.

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Waxy band between the plasma membranes of abutting root endodermal cells; forms a seal that prevents soil water from seeping through cell walls into the vascular cylinder.