Suppose I lift a weight of 1kg through 1metre, say from the floor to my waist height. The Potential Energy or work done against gravity is:
PE=mgh= 1kg x 9.81m/s^2 x 1m = 9.81J or approximately 10 Joules.
My question is: what happens to that Potential Energy when I return the weight to the floor? Clearly, if I simply release the weight from its 1m height, it will fall back to the floor and all of the Potential Energy will be converted into Kinetic Energy (until it hits the floor at speed). But what if, instead of dropping the weight, I slowly lower it and bring it gently to rest on the ground?
Is it correct to say that those 10Joules of Potential Energy are transferred to my body and converted into other forms, e.g. heat? (If not, then what happens to the Potential Energy?)