It takes a 100 kilogram 15.0 seconds to travel an unbanked circular track with a diameter of 20.0 m. Calculate the frictional force between the tires
and the pavement.

Does work output exceed work input when a machine is used? a) yes, it does, as machines create energy. b) it depends on the type of machine used. c) no, it doesn’t, as machines are inefficient. d) no, it doesn’t, as machines cannot create energy.