Write three differences between internal and external force?
Answers
Answer:
Internal forces are the forces that emanate from within a system. The system must be defined by you/problem. External forces are the forces that emanate from outside the system. ... Action or reaction force has no difference.
Answer:
Internal vs. External
This has to do with how you define a system. How you choose to do this is basically arbitrary but certain ways are beneficial in certain circumstances. An internal force is inside the system and an external force is outside the system. That might sound pretty meaningless and in some ways it is entirely arbitrary. But there is something very important. Only External Forces can cause an acceleration. The classic example of this I like to give is that you cannot grab yourself by the hair and lift yourself up off the ground. That is because your hand is part of your body. So you cannot really create a system where your hand is external to the rest of your body. Of course you could define the system to be your body minus your hand and say your hand is external to this system. But when your hand pulls on your hair, your hair will pull back on the hand. And since your whole body is connected, ultimately, there will be no acceleration of the center of mass of the hand-body system. But somone else could grab you by the hair and pull you up off the ground. Another classic example of this is the idea of pushing a car. Can you push your car from the inside? No. That is because you are inside the system. You could push on the windshield, but the windshield will push back on you. But if you get outside of the car, you can push on the car with the aid of the friction/traction from the gound.