Physics

Problem

Body A pushes body B with a force

\vec{F}_{A\to B}=4\,\hat{i}+9\,\hat{j}\,\text{N}

. Which vector represents the force exerted on A by B? a)

-4\,\hat{i}+9\,\hat{j}\,\text{N}

-4\,\hat{i}-9\,\hat{j}\,\text{N}

4\,\hat{i}+9\,\hat{j}\,\text{N}

9\,\hat{i}+4\,\hat{j}\,\text{N}