Initially, a Small 2

question 7

Multiple Choice

Initially, a small 2.0-kg rock is whirling at the end of a very thin string in a circular path of radius 0.75 m on a horizontal frictionless surface, as shown in the figure. The initial tangential speed of
The rock was 5.0 m/s. The string has been slowly winding around a vertical rod, and a few seconds
Later the length of the string has shortened to 0.25 m. What is the instantaneous speed of the mass at
The moment the string reaches a length of 0.25 m?

• A) 3.9 m/s
• B) 225 m/s
• C) 15 m/s
• D) 75 m/s
• E) 9.3 m/s

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Definitions:

Cube-Shaped Crystals

Crystalline structures that manifest in a cubic shape, common in minerals like pyrite and halite.

Pink-Colored Mineral

Minerals that exhibit a pink hue, often due to the presence of elements like manganese or inclusion of minerals like rhodonite.

Wavy Lines

This term is not typically associated with a standard definition in scientific contexts; it could refer to visual patterns or features that resemble waves.

Transparent

The quality of a material that allows light to pass through it without being scattered, making objects behind it visible.