Question

How does gravity affect potential energy?

Answer 1

This is more along the lines of "Does gravity affext potential energy" Sort of. Potential energy is an odd one to imagine, sometimes. It's the energy possessed by an object or system by dint of it's spatial and mechanical configuration. That definition alone is perhaps not so useful...and it's certainly not official. But what it means is that an object can potentially have energy due to where it is or what state the system is in. Imagine we have a box and it's on the floor. The box, for all intents and purposes, has no potential energy. It isn't going anywhere and it just sits on the floor. It can't do any work in it's current position. Now we hoist the box into the air. For any distance the box travels from the floor, it gains potential energy. Now let's back track. We've changed the box's spatial configuration by hoisting it into the air and so have given it potential energy. Why does it now have potential energy? Because we can now drop the box (costing us no energy) and the box will fall. Maybe it falls onto a passer-by and injures them. Box on the floor = No energy. We lift the box = We spend our energy and give the box potential energy (as it wants to fall toward the ground). We drop the box = Potential energy is converted to kinetic energy as the box falls. Box injures someone = The kinetic energy has done work upon the person. So we can see how it all flows and connects. We have to put energy into the box to fight against gravity, but you can't destroy or create energy....so the energy we've spent is potentially stored 'inside' the box. Clearly, gravity effects a LOT of potential energies around us. In fact to some small extent, it's probably impossible to entirely avoid it's effects.