If no energy is transferred, how much work is done?

Explanation:The potential energy is converted to kinetic energy in the process. But I see no transfer of energy between the earth and the body.

And how does energy transfer takes place in case of negative work ? When a body is moved across a surface which has friction, the friction does negative work. Does it mean that a sort of energy transfer occurs between the surface (source) and the body (object

the cells uses some of the atoms of the glucose molecules to atp molecules. the atoms of the glucose molecules will then be converted into energy which will be eventually stored in atp. the energy produced which are stored in atp are coming from the glucose’s chemical bonds.