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Humans are in motion, so it makes sense that Newton’s laws work on the body. They’re part of things you don’t see. Like the force of your heartbeat and the way blood moves in your veins and arteries.
But you can see the laws at work in how your knee bends. They’re in the nod of your head and the curl of your tongue. People sometimes have problems with their bodies. It’s up to biomedical engineers and others to solve them.