Energy doesn't get lost? Basic understanding, please If its true that energy isn't lost, its just transferred, where did the energy go from a falling object that hits the floor and stays there?
It started with the most gravitational potential energy, a second before it lands it is converted to kinetic energy, and the kinetic is at the peak. But after it fell and stopped, where is all the energy?
Also, it is said you can't create energy. But when an object is at rest on the floor it has no energy, and after being picked up it has energy.
I know these are basic questions, but I can't get to the bottom of this. 
 A: The object takes time to slow down.  
During the time it is slowing down heat is generated.
One way it could do this is by making an indent in the floor and the floor and the object rubbing together with frictional forces acting.
Sound will be generated by this will not be a significant amount of energy compared with the initial kinetic energy of the object.  
The falling object would do work permanently breaking bonds in itself and the floor.
Breaking bonds requires energy and this comes from the kinetic energy of the object.  
All the above assumes that the object does not rebound from the floor.  
If the object rebounds from the floor there must be a time when it is not moving ie the object has no kinetic energy.
To explain that imagine that the bonds between atoms can be thought of as little springs.
When a spring is compressed it stores elastic potential energy.
So as the object hits the floor it slows down and some of its kinetic energy is used to compressed the atomic springs (make the floor and the object contract) and so the kinetic energy is now elastic potential energy.  
The springs then expand and give up their elastic potential energy which is converted into the kinetic energy of the object.
If the object gets back all the kinetic energy it had before ie the kinetic energy is the same before and after the collision it is called an elastic collision otherwise it is called an inelastic collision.  
I must confess that I like this video which shows the deformation of a golf ball.
A: Some of it's kinetic energy that's transferred to the earth, some is sound/heat from the ball displacing air molecules.
A: When you pick up some object for example, the object itself gets the gravitational potential energy. However this energy was supplied by you converting your chemical energy into object's potential energy through your muscles. So its just energy conversion not creation! 
