All Flashcards
What is the effect of an external force on a system's center of mass?
It changes the motion of the center of mass.
What is the effect of the weight of a real string on the tension?
The weight causes the tension to vary along the length of the string.
Define Newton's Third Law.
For every action, there is an equal and opposite reaction.
What is an internal force?
A force between objects within a system.
What is an external force?
A force between an object in the system and something outside the system.
Define tension.
The pulling force transmitted through a string, cable, or similar object when it's pulled tight.
What is an ideal pulley?
A simple machine that changes the direction of a tension force.
What is the effect of pushing on a wall?
The wall exerts an equal and opposite force back on you.
What happens when internal forces act within a system?
The motion of the system's center of mass does not change.
What happens when an external force acts on a system?
The motion of the system's center of mass changes.
What is the effect of pulling on an ideal string?
Tension is created uniformly throughout the string.
What is the effect of pulling on a non-ideal string?
Tension is created, but it is not uniform throughout the string; it is greater at the top.