A motorist starting a car from rest accelerates uniformly to a speed of $v\, m/s$ in $9\, seconds$. He maintains this speed for another $50\, seconds$ and then applies the brakes and decelerates uniformly to rest. His deceleration is numberically equal to three times his previous acceleration. Then the time during which the deceleration takes place is ..........$s$ :-

If $v = x^2 -5x + 4$, find the acceleration of particle when velocity of the particle is zero

A motor car moving with a uniform speed of $20\,m/\sec $ comes to stop on the application of brakes after travelling a distance of $10\,m$ Its acceleration is..........$m/{\sec ^2}$

The velocity-displacement graph describing the motion of a bicycle is shown in the figure.

The acceleration-displacement graph of the bicycle's motion is best described by

A particle moves in a straight line so that its displacement $x$ at any time $t$ is given by $x^2=1+t^2$. Its acceleration at any time $\mathrm{t}$ is $\mathrm{x}^{-\mathrm{n}}$ where $\mathrm{n}=$ . . . . .

The displacement of a particle, moving in a straight line, is given by $s = 2{t^2} + 2t + 4$ where $s$ is in metres and $t$ in seconds. The acceleration of the particle is........$ms^{-2}$