The Two Masses in the Figure Are Released from Rest

question 68

Multiple Choice

The two masses in the figure are released from rest.After the 3.0-kg mass has fallen 1.5 m,it is moving with a speed of 3.8 m/s.What is the change in mechanical energy done on the system during this time interval by the frictional force on the 2.0 kg mass?

• A)-12 J
• B)-17 J
• C)-20 J
• D)-8.0 J
• E)-28 J

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Definitions:

Autonomic Nervous System

The part of the nervous system that controls involuntary bodily functions, such as heart rate and digestion.

Sympathetic Nervous System

Part of the autonomic nervous system that prepares the body for quick action in emergencies; "fight or flight" response.

Parasympathetic Nervous System

Part of the autonomic nervous system responsible for rest and digestion, counterbalancing the sympathetic nervous system's fight or flight response.

Behavioral Observation

A method used in psychological research and practice where the actions or behaviors of subjects are watched and recorded.