An object at rest at the origin begins to move in the $+x$-direction with a uniform acceleration of $1 \, m/s^2$ for $4 \, s$ and then it continues moving with a uniform velocity of $4 \, m/s$ in the same direction. The $x-t$ graph for the object's motion will be:

$A$ bird flies with a velocity $(t-2) \text{ m/s}$ along a straight line, where $t$ is the time in seconds. The distance covered by it in a time of $4 \text{ s}$ is: (in $\text{ m}$)

The variation of velocity of a particle moving along a straight line with time is illustrated in the following figure. The distance travelled by the particle in $4 \, s$ is: (in $, m$)

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 $t_2$?
$(a)$ $x(t_2) = x(t_1) + v(t_1)(t_2 - t_1) + (1/2)a(t_2 - t_1)^2$
$(b)$ $v(t_2) = v(t_1) + a(t_2 - t_1)$
$(c)$ $v_{\text{average}} = (x(t_2) - x(t_1)) / (t_2 - t_1)$
$(d)$ $a_{\text{average}} = (v(t_2) - v(t_1)) / (t_2 - t_1)$
$(e)$ $x(t_2) = x(t_1) + v_{\text{average}}(t_2 - t_1) + (1/2)a_{\text{average}}(t_2 - t_1)^2$
$(f)$ $x(t_2) - x(t_1) = \text{area under the } v-t \text{ curve bounded by the } t\text{-axis and the dotted lines shown.}$

Which of the following velocity-time graphs is physically not possible?

$A$ batsman hits a sixer and the ball touches the ground outside the cricket ground. Which of the following graphs describes the variation of the cricket ball's vertical velocity $v$ with time between the time $t_1$ as it hits the bat and time $t_2$ when it touches the ground?