# Velocity and Acceleration

Calculus Level pending

A particle moves according to the following movement's law:

$$\vec{r}(t)=(3{ t }^{ 2 }+5)\vec{{ E }_{ x }} - 2t\vec{{ E }_{ y }} (I.S.)$$

For $$t=1s$$, calculate the angle between $$\vec{v}$$ and $$\vec{a}$$.

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