All Flashcards
What is Newton's Third Law?
For every action, there is an equal and opposite reaction.
Define internal forces.
Forces between objects within a system.
Define external forces.
Forces between an object in the system and something outside the system.
What is tension?
The pulling force transmitted through a string, cable, or similar object when it's pulled tight.
What is an ideal string?
An ideal string has negligible mass and doesn't stretch.
What is an ideal pulley?
A simple machine that changes the direction of a tension force with negligible mass and friction.
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.
What are the differences between internal and external forces?
Internal Forces: Act within the system, do not affect the center of mass motion. | External Forces: Act on the system from outside, do affect the center of mass motion.
Compare real and ideal strings.
Ideal Strings: Negligible mass, inelastic, constant tension. | Real Strings: Have mass, can stretch, tension may vary.