Some silly questions I've just never been able to figure out, and it really bothers me when I don't know if something is a concept like speed, or just a way of describing something else and not in itself tangible. If anyone could take the time to clear these (or some of them) up for me, it would be greatly appreciated. - What exactly is torque? Is it actually some special sort of force, or is it just a normal force that just happens to rotate an object because the object is rotatable or because the direction of the force just happens to be such? - What does it mean that inertia is an object's "resistance" to change? How is the object resisting? Is inertia just a way of saying it takes a force to speed up/slow down an object? What is the difference between mass and inertia? - Momentum: If an object is resting on top of another object, and we push it so it falls off to the right, does the other object move left even when there is no friction between them? Why? Please explain momentum conservation. - When we say an object has potential energy, for example gravitational potential e., is this just the potential, or does the object literally gain energy? Does an object on the table literally have more "stored" energy than the same object on the ground? How? Same with kinetic energy.