Tangential acceleration of a particle moving in a circle of radius $1$ $m$ varies with time $t$ as (initial velocity of particle is zero). Time after which total acceleration of particle makes and angle of $30^o$ with radial acceleration is
$4 \,\, sec$
$4/3 \,\, sec$
$2^{2/3} \,\,sec$
$\sqrt 2 \,\, sec$
Which of the following is not a projectile?
The height $y$ and the distance $x$ along the horizontal plane of a projectile on a certain planet (with no surrounding atmosphere) are given by $y = (8t - 5{t^2})$ meter and $x = 6t\, meter$, where $t$ is in second., the acceleration due to gravity is given by ......... $m/{\sec ^2}$
At time $t =0$ a particle starts travelling from a height $7\,\hat{z} cm$ in a plane keeping $z$ coordinate constant. At any instant of time it's position along the $x$ and $y$ directions are defined as $3\,t$ and $5\,t^{3}$ respectively. At $t =1\,s$ acceleration of the particle will be.
What can be the angle between velocity and acceleration for the motion on a straight line ? Explain with example.