1. a body continues to be in state of rest or uniform motion until it is acted upon by an external force. 2. for every action, there is equal a n opposite reaction.
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1.Every object in a state of uniform motion tends to remain in that state of motion unless
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If you speak of a proof in a mathematical sense, then you always have to consider from which assumptions you want to prove something. If you assume conservation of momentum and Newtons
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Around 1665.
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