The velocity of bullet is reduced from $200\; m / s$ to $100\; m / s$ while travelling through a wooden block of thickness of $10 \;cm$ . The retardation assuming to be uniform, will be ...........$\times {10^4}\, m/s^2$

The displacement of a particle as a function of time is shown in Figure. It indicates :-

A parachutist drops freely from an aeroplane for $10\,s$ before the parachute opens  out. Then he descends with a net retardation of $2.5\, m/s^2$. If he bails out of the  plane at a height of $2495\, m$ and $g = 10\, m/s^2$, hit velocity on reaching the  ground will be .......$m/s$

A thief is running away on a straight road on a jeep moving with a speed of $9\, m/s$. A police man chases him on a motor cycle moving at a speed of $10 \,m/s$. If the instantaneous separation of jeep from the motor cycle is $100 \,m$, how long will it take for the policemen to catch the thief........ $second$

A particle is projected with velocity $v_0$ along $x-$ axis and its decelaration on the particle is a $a= -\alpha x^2$. The distance at which the particle stops is

Acceleration versus velocity graph of a particle moving in a straight line starting from  rest is as shown in figure. The corresponding velocity-time graph would be