Work done by driving Force = change in K.E + Change in P.E – Workdone against re

Question

Work done by driving Force = change in K.E + Change in P.E – Workdone against resistance

This equation is a misconception in physics, where the actual equation should be

Work done by driving Force = change in K.E + Change in P.E + Workdone against resistance

Students reasoned that: since Resistance is a force which opposes motion, the work done against any resistive forces must be subtracted from the work/Energy equation.

can i have an explanation why this is a misconception and how can i explain the real equation

Work done by driving Force = change in K.E + Change in P.E – Workdone against resistance

This equation is a misconception in physics, where the actual equation should be

Work done by driving Force = change in K.E + Change in P.E + Workdone against resistance

Students reasoned that: since Resistance is a force which opposes motion, the work done against any resistive forces must be subtracted from the work/Energy equation.

can i have an explanation why this is a misconception and how can i explain the real equation

Explanation / Answer

What student should atually write is:
Work done by driving Force – Workdone against resistance = change in K.E + Change in P.E;
Because the total work done on the system is equal to the Change in Mechanical enrgy of the system (By Principle of conservation of energy).

Thus,
Work done by driving Force = change in K.E + Change in P.E + Workdone against resistance

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