A point moves in a straight line so that its displacement $x\,m$ at time $t\,sec$ is given by $x^2 = 1 + t^2$. Its acceleration in $m/sec^2$ at a time $t\,sec$ is
$1/x^3$
$-t/x^3$
$\frac{1}{x} - \frac{{{t^2}}}{{{x^3}}}$
$\frac{1}{x} - \frac{{{1}}}{{{x^2}}}$
$Assertion$ : Retardation is directly opposite to the velocity.
$Reason$ : Retardation is equal to the time rate of decrease of speed.
From the $v-t$ graph, the
For the acceleration-time $(a-t)$ graph shown in figure, the change in velocity of particle from $t=0$ to $t=6 \,s$ is ........ $m / s$
A car moving along a straight highway with speed of $126 \;\mathrm{km} h^{-1}$ is brought to a stop within a distance of $200\; \mathrm{m}$. how long(in $seconds$) does it take for the car to stop?
The displacement of a particle is given by $y = a + bt + c{t^2} - d{t^4}$. The initial velocity and acceleration are respectively