Is a spring a simple machine?
No, a simple machine (in general) means that you put energy into a simple machine at a certain force and over a certain distance and you get a different force (greater or lesser force) over a different distance. (if you gain force using a simple machine than you necessary lose speed and distance) A spring only (at best) gives you the exact same energy that you put into the spring and also gives you that energy with the exact same force that you put in. It seems like a simple machine only because it stores energy and you can slowly charge it but quickly discharge it, giving the illusion of gaining speed or force.
