question_answer

  A car is moving horizontally on a surface along a straight line at constant speed. Is any force acting on it? If not, why is the fuel required to run it?

Answer:

                  The car moves with constant velocity. So no unbalanced force acts on it.                        (1) The fuel is used to move the car with a force which balances with the force of friction exerted by the surface.                                  (1)