A particle experiences a constant acceleration for $20 \,sec$ after starting from rest. If it travels a distance ${S_1}$ in the first $10\, sec$ and a distance ${S_2}$ in the next $10 \,sec$, then
${S_1} = {S_2}$
${S_1} = {S_2}/3$
${S_1} = {S_2}/2$
${S_1} = {S_2}/4$
A body starts from origin and moves along $x$-axis so that its position at any instant is $x=4 t^2-12 t$ where $t$ is in second and $v$ in m/s. What is the acceleration of particle is ............. $m / s ^2$
The position, velocity and acceleration of a particle moving with a constant acceleration can be represented by
A particle starts from rest and traverses a distance $l$ with uniform acceleration, then moves uniformly over a further distance $2 l$ and finally comes to rest after moving a further distance $3 l$ under uniform retardation. Assuming entire motion to be rectilinear motion the ratio of average speed over the journey to the maximum speed on its ways is
A motor car moving at a speed of $72\,km / h$ cannot come to a stop in less than $3.0\,s$ while for a truck this time interval is $5.0\,s$. On a highway, the car is behind the truck both moving at $72\,km / h$. The truck gives a signal that it is going to stop at emergency. At what distance the car should be from the truck so that it does not bump onto (collide with) the truck. Human response time is $0.5\,s ...........\,m$