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

---

Definitions:

Carbohydrates

Organic compounds made up of carbon, hydrogen, and oxygen that are a major source of energy for the body, found in foods like grains, fruits, and vegetables.

Energy Calories

A unit of measure that indicates the amount of energy that food provides to the body.

Exocrine Gland

A type of gland that releases its secretions through ducts to an external or internal surface, such as sweat, salivary, and digestive glands.

Ducts

Channels or tubes in the body through which fluids or other substances are transported or secreted.