Q.Justify the statement, "Work and energy are the two sides of a coin".

[!TLDR] Work done on a body converts directly into its kinetic energy (work-energy theorem), so 'work' and 'energy' are two ways of describing the same underlying physical change, not two separate things. [!ANSWER] Work done equals the r …

'Two sides of a coin' means work and energy are not two independent, unrelated ideas, but two complementary DESCRIPTIONS of the very same underlying physical transaction. The WORK-ENERGY THEOREM (4.6) makes this precise: the work done on (or by) a body is exactly equal to the resulting change in its kinetic energy, $W=\Delta(KE)$ (for a purely conservative interaction), or more generally, decrease in potential energy = increase in kinetic energy + work done against non-conservative forces. Whenever a force does work on a body, that work manifests itself as a change in the body's energy (kinetic or, via the potential-energy relation $dU=-F\,dx$, potential); conversely, whenever a body's kinetic or potential energy changes, it is because some force has done a corresponding amount of work on (or against) it. Neither concept can be meaningfully discussed in complete isolation from the …

Invoke the work-energy theorem to show that 'work done' and 'change in energy' are numerically and concep …

Treating work and energy as separate 'topics' rather than recognising the work-energy theor …