An object moving along horizontal $x$-direction with kinetic energy 10 J is displaced through $\vec{

Question

An object moving along horizontal $x$-direction with kinetic energy 10 J is displaced through $\vec{x}=(3 \hat{i}) \mathrm{m}$, by the force $\vec{F}=(-2 \hat{i}+3 \hat{j}) \mathrm{N}$. The kinetic energy of the object at the end of the displacement $x$ is

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(c) : Given, $\vec{F}=(-2 \hat{i}+3 \hat{j}) \mathrm{N}$ or $x=(3 \hat{i}) \mathrm{m}$ Initial Kinetic energy, $\left(K_iight)=10 \mathrm{~J}$ $ W=\vec{F} \cdot \vec{x}=(-2 \hat{i}+3 \hat{j}) \cdot(3 \hat{i})=-6 \mathrm{~J} $ \ Using work-energy theorem, \ $W=\Delta K . E$. $-6=K_f-K_i \quad$ or $-6=K_f-10 ; K_f=4 \mathrm{~J}$