Well i known this is a kinda fundamental property of mechanics but i always have a weird thinking about this law.(adsbygoogle = window.adsbygoogle || []).push({});

Let me illustrate my trouble with an example.

Let's say i kick a ball with force F? According to the Law the ball experience F force, and my leg experiences -F. My questions are:

1. Where is the Force -F actually came from? Since i am the only one putting energy on the ball. How come the ball have energy to exert force -F to me?

2. Let's say if the answer for question 1 is due to me too, does this imply i have to use twice the energy to produce F and -F??

(Sorry i think i am kinda confused as well...I be very happy and glad if anyone with clear mind here can help me solve this dilemma. Thanks a lot)

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# Newton's third law

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