Question

The adjacent figure shows an interaction force between two particles A and B against the separation between them, when the separation between them changes from zero to infinity. Parts of the curve above and below the x-axis denote attractive and repulsive forces respectively. Then, which of the following statement is incorrect?

• A. Kinetic energy of the system increases from $x_1$ to $x_2$
• B. Potential energy of the system decreases from $x_1$ to $x_2$
• C. Kinetic energy of the system increases from $x_3$ to $x_4$
  
• D. Kinetic energy of the system decreases from $x_3$ to $x_4$

Answer 1

The correct option is C Kinetic energy of the system increases from $x_3$ to $x_4$


From $x_1$ to $x_2$ interaction force is repulsive, so potential energy decreases and from $x_3$ to $x_4$ interaction force is attractive, so kinetic energy decreases.