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1. What is the potential energy of a system in the state of unstable equilibrium ?

2. A ball of mass 5 kg experiences a force F = 2xsquare + x . workdone in displacing the ball by 2 m is ?

3. a body is acted upon by a force F = - i cap + 2 j cap + 3 k cap . what is the work done by the force in displacing it from (0,0,0) to (0,0,4 m) ?

Please find below the solution to the asked query:

$\text{1.Thepotentialenergyforaunstableequilibriumismaximum.}\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\text{2.Theworkdoneisgivenby}\phantom{\rule{0ex}{0ex}}W={\int}_{0}^{2}F.dx={\int}_{0}^{2}(2{x}^{2}+x)dx=\frac{22}{3}\text{J}\phantom{\rule{0ex}{0ex}}\text{3.Herethedisplacementis}\phantom{\rule{0ex}{0ex}}\overrightarrow{d}=(0-0)\hat{i}+(0-0)\hat{j}+(4-0)\hat{k}=4\hat{k}\phantom{\rule{0ex}{0ex}}\text{Soworkdoneis}\phantom{\rule{0ex}{0ex}}\overrightarrow{F}\xb7\overrightarrow{d}=(-\hat{i}+2\hat{j}+3\hat{k})\xb74\hat{k}=12\text{J}$

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