Why is the work output of a machine never equal to the work input? a. some work input is used to overcome friction. b. input distance never equals output distance. c. some work output is used to overcome friction.

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?

A( developed during the process of technology design

Do you think you could give me the answers to #29?