At time $$\(t\)$$ seconds $$\((t \geqslant 0)\)$$, a particle $$\(P\)$$ has velocity $$\(\mathbf{v ~ m ~ s} \mathrm{s}^{-1}\)$$, where $$\[ \mathbf{v}=\left(3 t^{2}-9 t+6\right) \mathbf{i}+\left(t^{2}+t-6\right) \mathbf{j} \]$$ (a) Find the acceleration of $$\(P\)$$ when $$\(t=3\)$$ (3) When $$\(t=0, P\)$$ is at the fixed point $$\(O\)$$. The particle comes to instantaneous rest at the point $$\(A\)$$. (b) Find the distance $$\(O A\)$$. (7)

Answer:

Knowledge points:

Solution: