Physics - Center of Mass Question with Solution | TestHub

The line of centres is the x-axis; equal masses exchange their x-components in an elastic collision.$v_{Ax}^{\prime }=v_{Bx}=-10\cos 37^{\circ }=-8\mathrm{m}/\mathrm{s}$, and A has no y-component:${\vec{v}}_A^{\prime }=-8\hat{i}\mathrm{m}/\mathrm{s}$, so (A) is correct.${\vec{v}}_B^{\prime }=6\hat{i}-6\hat{j}\mathrm{m}/\mathrm{s}$ (its y-component is unchanged), so (B) as printed is false. Impulse on$\mathrm{A}=2(-8-6)\hat{i}=-28\hat{i}\mathrm{Ns}$, so (C) is correct. B's KE loss$=\frac{1}{2}(2)\left(10^2\right)-\frac{1}{2}(2)\left(6^2+6^2\right)=100-72=28\mathrm{J}$, so (D) is correct. Answer: (A), (C), (D)