Question

A particle is taken from point A to point B under the influence of a force field. Now it is taken back from B to A and it is observed that the work done in taking from A to B is not equal to the work done in taking from B to A. If $W_{nc}$ and $W_c$ are the works done by non-conservative forces and conservative forces present in the system respectively, $\Delta U$ is the change in potential energy, $\Delta K$ is the change in kinetic energy, then which of the following is wrong?

• A. $W_{nc}-\Delta U=\Delta K$
• B. $W_c=-\Delta U$
• C. $W_{nc}+W_c=\Delta K$
• D. $W_{nc}-\Delta U=-\Delta K$

Answer 1

The correct option is D $W_{nc}-\Delta U=-\Delta K$

Use Work – Energy theorem