A Machinist Turns on the Power on to a Grinding $96 \mathrm { rad } / \mathrm { s }$

question 78

Multiple Choice

A machinist turns on the power on to a grinding wheel at time t = 0 s. The wheel accelerates uniformly from rest for 10 s and reaches the operating angular speed of $96 \mathrm { rad } / \mathrm { s }$ The wheel is run at that angular velocity for 40 s and then power is shut off. The wheel slows down uniformly at $1.5 \mathrm { rad } / \mathrm { s } ^ { 2 }$ until the wheel stops. For how long a time after the power is shut off does it take the wheel to stop?

• A) 64 s
• B) 62 s
• C) 66 s
• D) 68 s
• E) 70 s

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Definitions:

New Life Forms

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Permanent Settlements

Communities where people establish long-term residences, marking a shift from nomadic lifestyles to settled agriculture and urban development.

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In the social sciences, it refers to the process by which vague opinions or beliefs become solidified into clear and distinct ideas or ideologies.

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Use machines and fuel to greatly increase the supply and dependability of food and finished goods. The first such societies emerged about 225 years ago in Great Britain. Productivity, the division of labor, and average settlement size increased substantially in industrial societies compared with agricultural societies. While social inequality was substantial during early industrialism, it declined as the industrial system matured.