If the velocity $\left( {in\,\,m{s^{ - 1}}} \right)$ of a particle is given by $4\widehat i + 5t\widehat j$, then the magnitude of its acceleration $\left( {in\,\,m{s^{ - 2}}} \right)$ is

A bullet emerges from a barrel of length 1.2 m with a speed of $640\,\,m{s^{ - 1}}$. Assuming constant acceleration the approximate time that its spends in the barrel after the gun is fired is

A car travels half the distance with constant velocity of 40 kmph and the remaining half with a constant velocity of 60 kmph. The average velocity of the car in kmph is

If the velocity of a particle is $\upsilon \,{\rm{ = }}\,{\rm{At}}\,{\rm{ + }}\,{\rm{B}}{{\rm{t}}^2}$, where A and B are constants, then the distance travelled by it between 1s and 2s is:

A particle starts from rest and moves along a straight line with an acceleration given by $a = 6t - 4$, where $a$ is in $m/s^2$ and $t$ is in seconds. At what time is the velocity of the particle zero after the start of motion?

A train travelling with an initial velocity $u$ begins to decelerate uniformly. After travelling 500 m, its velocity becomes $\frac{u}{2}$. How much further will it travel before coming to a complete stop?

A drone's horizontal and vertical positions are given by $x = 6t - t^2$ and $y = 4t$, respectively (in meters and seconds). At what time is the drone's vertical acceleration equal to zero?

A particle comes round a circle of radius 1 m once. The time taken by it is 10 sec. The average velocity of motion is

The average velocity of a body moving with uniform acceleration travelling a distance of 3.06 m is $0.34\,\,m{s^{ - 1}}$. If the change in velocity of the body is $0.18\,\,m{s^{ - 1}}$ during this time.

A particle starts from rest and travels a distance s with uniform acceleration, then it travels a distance 2s with uniform speed, finally it travels a distance 3s with uniform retardation and comes to rest. If the complete motion of the particle in a straight line then the ratio of its average velocity to maximum velocity in

A car travels equal distances in the same direction with velocities $60{\rm{km}}{{\rm{h}}^{ - 1}}\,,\,20\;{\rm{km\;}}{{\rm{h}}^{ - 1}}$ and $10\;{\rm{km\;}}{{\rm{h}}^{ - 1}}$ respectively. The average velocity of the car over the whole journey of motion is