The position vector of a particle changes with time according to the relation $\vec r\left( t \right) = 15{t^2}\hat i + \left( {4 - 20{t^2}} \right)\hat j$. What is the magnitude of the acceleration at $t = 1$ ?
$40$
$100$
$25$
$50$
What can be the angle between velocity and acceleration for the motion in two or three dimension ?
Two particles are projected simultaneously in the same vertical plane, from the same point on ground, but with same speeds but at different angles $( < 90^o )$ to the horizontal. The path followed by one, as seen by the other, is
The displacement $x$ of a particle depend on time $t$ as $x = \alpha {t^{^2}} - \beta {t^3}$
The position of a particle moving in the $xy-$ plane at any time $t$ is given by $x = (3t^2 -6t)\, metres$, $y = (t^2 -2t)\,metres$. Select the correct statement about the moving particle from the following