Question

neglecting friction, which of the following statements describes the relationship between the energy of an object and the work done on it? a work is needed for an object to keep a constant kinetic energy. b work is needed for an object to keep a constant potential energy. c increasing the kinetic energy of an object increases the amount of work needed to stop it. d increasing the potential energy of an object decreases the amount of work needed to stop it.

Explanation:

According to the work - energy theorem, the net work done on an object is equal to its change in kinetic energy ($W=\Delta K$). To stop an object, the work done on it is equal to its initial kinetic energy. So, if the kinetic energy of an object is increased, more work is needed to stop it. An object can keep a constant kinetic or potential energy without work being done on it (in the absence of non - conservative forces like friction). Also, potential energy is not directly related to the work needed to stop an object in the way described in option D.

Answer:

C. Increasing the kinetic energy of an object increases the amount of work needed to stop it.