Specialist2025 Exam 2 Section A · Q16CAS active1 mark

Acceleration perpendicular to velocity

The position vector of a particle at time $t$ is given by $\tvec{r}(t) = ne^{-2t}\tvec{i} - t^2\tvec{j}$ , where $n$ is a positive constant.

For what value of $n$ is the particle's acceleration perpendicular to its velocity when $t = \frac{1}{2}$ ?

1 mark

2e

\frac{e^{0.5}}{2}

\frac{e}{2}

\frac{e}{2\sqrt{2}}

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