Two balls are projected horizontally from the same height with different initial speeds. Neglecting air resistance, which statement is true about their times of flight?

A car is travelling at $72{\rm{\;km}}{{\rm{h}}^{ - 1}}$ and is 20 m from a barrier when the driver puts on the brakes. The car hits the barrier 2s later. What is the magnitude of the constant deceleration?

A particle starts its motion from rest under the action of a constant force. If the distance covered in first 10 seconds is ${S_1}$ and that covered in the first 20 seconds is ${S_2}$ , then

A car moves from X to Y with a uniform speed ${v_u}$ and returns to Y with a uniform speed ${v_d}$. The average speed for this round trip is

The effective acceleration of a body, when thrown upwards with acceleration a will be

The $x{\rm{ \;and \;}}y$ coordinates of the particle at any time are $x = 5t - 2{t^2}{\rm{ \;and\; }}y = 10t$ respectively, where $x{\rm{ \;and\; }}y$ are in meters and $t$ in seconds. The acceleration of the particle at $t = 2s$ is

The $x{\rm{ \;and \;}}y$ coordinates of the particle at any time are $x = 5t - 2{t^2}{\rm{ \;and\; }}y = 10t$ respectively, where $x{\rm{ \;and\; }}y$ are in meters and $t$ in seconds. The acceleration of the particle at $t = 2s$ is

Two bikes $P$ and $Q$ are moving along a straight track. Their positions are given by $x_P(t) = 3t + t^2$ and $x_Q(t) = 7t - 2t^2$. At what time do the bikes have the same velocity?

A body starts from rest, with uniform acceleration. If its velocity after n seconds is v,then its displacement in the last two seconds is

The position coordinates of a particle moving in X-Y as a function of time t are $\;\;x = 2{t^2} + 6t + 25\,,\,y = {t^2} + 2t + 1$ The speed of the object at t=10 s is approximately

A stone is thrown vertically upwards with an initial velocity $u$. After reaching a height $h$, its velocity becomes $\frac{u}{2}$. What is the maximum height reached by the stone?