TOPIC 2.3 Newton’s Third Law

Front

What does Newton’s third law describe?

Back

Describes the interaction of two objects in terms of the paired forces that each exerts on the other.

Front

How do internal forces within a system affect the motion of the system’s center of mass?

Back

Do not influence the motion of a system’s center of mass.

Front

What is tension in a string, cable, or chain in response to external forces?

Back

The macroscopic net result of forces that segments exert on each other in response to an external force.

Front

What are the characteristics of an ideal string?

Back

Has negligible mass and does not stretch when under tension.

Front

What is true about tension at all points in an ideal string?

Back

Is the same at all points within the string.

Front

What is true about the tension in a string with nonnegligible mass?

Back

May not be the same at all points within the string.

Front

What defines an ideal pulley?

Back

A pulley with negligible mass that rotates about an axle through its center of mass with negligible friction.