A person uses a pulley to raise a flag up a 15 meter flagpole. The weight of the flag is 45 Newtons. The person pulls down on the rope with a force of
50 Newtons through a distance of 15 meters.

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).