Question

This question is not easy but i hope u cn answer it. Plz answer ques no. 7 lets see who is real brainlist

Answer 1

$\vec{r}=2t\hat{i}+2t^2\hat{j}\\\Rightarrow \vec{v}=2\hat{i}+4t\hat{j}\\\Rightarrow \tan\theta=\dfrac{4t}{2}=2t\\\Rightarrow {\sec}^2\theta\dfrac{d\theta}{dt}=2\\\Rightarrow\dfrac{d\theta}{dt}=\dfrac{2}{1+{\tan}^2\theta}\\=\dfrac{2}{1+(2t)^2}=\dfrac{2}{1+4^2}=\dfrac{2}{17}rad/s$