A particle starts from rest and performing circular motion of constant radius with speed given by $v = \alpha \sqrt x$ where $\alpha$ is a constant and $x$ is the distance covered. The correct graph of magnitude of its tangential acceleration $(a_t)$ and centripetal acceleration $(a_c)$ versus $t$ will be:

A particle moves $21\, m$ along the vector $6\hat i + 2\hat j + 3\hat k$ , then $14\, m$ along the vector $3\hat i - 2\hat j + 6\hat k$ . Its total displacement (in meters) is

The position of a particle moving in the $xy-$plane at any time $t$ is given by $x = (3{t^2} - 6t)$ metres, $y = ({t^2} - 2t)$ metres. Select the correct statement about the moving particle from the following

A particle moves in the $xy$ -plane with velocity $u_x = 8t -2$ and $u_y = 2$. If it passes through  the point $(14, 4)$ at $t = 2\, s$, the equation of its path is 

Velocity-time graph for a car is semicircle as shown here. Which of the following is correct :

A particle moves along a parabolic path $y=9 x^2$ in such a way that the $x$ component of velocity remains constant and has a value $\frac{1}{3}\,m / s$. The acceleration of the particle is $.......m / s ^2$