The distance travelled by a particle is related to time $t$ as $x = 4t^2$. The velocity of the particle at $t = 5 \, s$ is $......... \, ms^{-1}$.

$A$ bird flies for $4 \, s$ with a velocity of $|t - 2| \, m/s$ in a straight line,where $t$ is time in seconds. It covers a distance of ......... $m$.

The $x-t$ graph for a uniformly accelerated particle is as shown in the figure. Find the average velocity between points $(i)$ and $(ii)$ in $ms^{-1}$.

The velocity-time graph of a particle in one-dimensional motion is shown in the figure. Which of the following formulae are correct for describing the motion of the particle over the time-interval $t_1$ to $t_2$?
$(a)$ $x(t_2) = x(t_1) + v(t_1)(t_2 - t_1) + (1/2)a(t_2 - t_1)^2$
$(b)$ $v(t_2) = v(t_1) + a(t_2 - t_1)$
$(c)$ $v_{\text{average}} = (x(t_2) - x(t_1)) / (t_2 - t_1)$
$(d)$ $a_{\text{average}} = (v(t_2) - v(t_1)) / (t_2 - t_1)$
$(e)$ $x(t_2) = x(t_1) + v_{\text{average}}(t_2 - t_1) + (1/2)a_{\text{average}}(t_2 - t_1)^2$
$(f)$ $x(t_2) - x(t_1) = \text{area under the } v-t \text{ curve bounded by the } t\text{-axis and the dotted lines shown.}$

$A$ train starting from rest accelerates uniformly for $100\,s,$ then comes to a stop with a uniform retardation in the next $200\,s.$ During the motion,it covers a distance of $3\,km.$ Choose the wrong option.

What is the maximum acceleration of the train during the journey in $km \ h^{-2}$?