For a sphere rolling freely on a flat elastic surface,energy loss is usually refered to the elastic hysteresis lossee. The value of the elastic hysteresis loss coefficient is constant and function of the elastic properties of the contacting materials.
In the present work,the experimental results showed that soft lead films behave elastically under the application of high values of normal force.It is also shown that the elastic hys-teresis loss coefficient is,not only a function of the elastic properties of the contacting material,but also function of the normal load.The relationship between the value of the elastic hysteresis loss coefficient, for lead and silver films on heel substrate,and the normal force is presented together with the measured value for the uncoated steel surface which took a constant value.