You can also see this directly from Equation (\ref{eq:7.5}), by choosing the \(x\) axis to point in the direction of the force (so \(F_y\) = \(F_z\) = 0), and the displacement to point along any of th...You can also see this directly from Equation (\ref{eq:7.5}), by choosing the \(x\) axis to point in the direction of the force (so \(F_y\) = \(F_z\) = 0), and the displacement to point along any of the other two axes (so \(\Delta x\) = 0): the result is \(W\) = 0. So—for this very simple system—we could rephrase the result (\ref{eq:7.11}) by saying that the work done by the net external force acting on the system (the particle in this case) is equal to the change in its total energy.
