All Flashcards
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 are the key differences between internal and external forces?
Internal forces: Act within a system, do not affect center of mass motion. | External forces: Act on the system from outside, do affect center of mass motion.
Differentiate between real and ideal strings regarding tension.
Ideal strings: Tension is constant throughout. | Real strings: Tension can vary due to the string's weight.
What is the effect of an external force on a system?
It changes the motion of the system's center of mass.
What is the effect of the weight of a real string on the tension?
The tension varies along the length of the string, usually being maximum at the top.
What is the effect of pushing on a wall?
The wall pushes back on you with an equal and opposite force.
What is the effect of internal forces acting within a system?
They cancel each other out and do not affect the motion of the system's center of mass.
What is the effect of using multiple ideal pulleys in a block and tackle system?
They multiply the applied force, making it easier to lift heavy loads.