A particle accelerates from rest at a constant rate for sometime and attains a constant velocity of $8\, m s ^{-1}$. Afterwards it decelerates with a constant rate and comes to rest. If the total time taken is $4$ second, the distance travelled is
$32$ metre
$16$ metre
$4$ metre
insufficient data
What is the numerical ratio of average velocity to average speed of an object when it is moving along a straight path ?
A girl running a race accelerates at $2.5\, m s ^{-2}$ for the first $4\, s$ of the race. How far does she travel in this time ?
Following figure is the speed-time graph for a rocket from the moment when the fuel starts to burn, i.e. at time $t=0$.
$(a)$ State the acceleration of the rocket at $t=0$.
$(b)$ State what happens to the acceleration of the rocket between $t=5 s$ and $t=60 s$.
$(c)$ Calculate the acceleration of rocket at $t=80 s$ Give reason for your answer.
$(d)$ The total mass of the rocket at $t=80\, s$ is $1.6 \times 10^{6}\, kg .$ Calculate the resultant force on the rocket at this time. Give reason for your answer.
The velocity$-$time graph of an ascending passenger lift is as in the figure shown below
$(i)$ Identify the kind of motion of lift represented by lines $OA$ and $BC$.
$(ii)$ Calculate the acceleration of the lift
$(a)$ During the first two seconds.
$(b)$ Between the $3^ {r d}$ and $10^ {t h}$ second.
$(c)$ During the last two seconds.
Can you suggest about the kind of motion of a body from following distance$-$time graphs ?