A ship A is moving westwards with a speed of 10 km ${\mathrm{h}}^{-1}$ and a ship B, 100 km south of A is moving northwards with a speed of 10 km ${\mathrm{h}}^{-1}$. The time after which the distance between them becomes the shortest, is:

1. 5 hr

2. $5\sqrt{2}$ hr

3. $10\sqrt{2}$ hr

4. 0 hr

Time taken by the projectile to reach from A to B is t. Then the distance AB is equal to :

1. $\frac{ut}{\sqrt{3}}$

2. $\frac{\sqrt{3}ut}{2}$

3. $\sqrt{3}ut$

4. 2ut

A particle projected with kinetic energy ${\mathrm{k}}_0$ with an angle of projection $\mathrm{\theta }$. Then the variation of kinetic K with vertical displacement y is

1.  linear

2.  parabolic

3.  hyperbolic

4.  periodic

A river is flowing with a speed of 1 km/hr. A swimmer wants to go to point 'C' starting from 'A'. He swims with a speed of 5 km/hr, at an angle $\theta$ with respect to the river. If $\text {AB = BC = 400 m}$. Then

1. The time taken by the man is 12 min

2. The time taken by the man is 8 min

3. The value of $\theta$ is 45$°$

4. The value of $\theta$ is 53$°$

 A body is thrown horizontally with a velocity $\sqrt{2 g h}$ from the top of a tower of height $h$. It strikes the level ground through the foot of the tower at a distance $x$ from the tower. The value of $x$ is:

Two men $P$ and $Q$ are standing at corners $A$ and $B$ of a square $ABCD$ of side $8~\text m.$ They start moving along the track with a constant speed $2~\text{m/s}$ and $10~\text {m/s}$ respectively. The time when they will meet for the first time is equal to:
       
1. $2~\text{sec}$
2. $3~\text{sec}$
3. $1~\text{sec}$
4. $6~\text{sec}$ 

A particle starts from the origin at t=0 and moves in the x-y plane with constant acceleration 'a' in the y direction. Its equation of motion is $y=b{x}^2$. The x component of its velocity (at t=0) is:

1. variable

2. $\sqrt{\frac{2a}{b}}$

3. $\frac{a}{2b}$

4. $\sqrt{\frac{a}{2b}}$

A body is projected with a velocity $u$ with an angle of projection $\theta.$ The change in velocity after the time $(t)$ from the time of projection will be:

What determines the nature of the path followed by the particle?

1. Speed only

2. Velocity only

3. Acceleration only

4. None of these

A boat is sent across a river in perpendicular direction with a velocity of 8 km/hr. If the resultant velocity of boat is 10 km/hr, then velocity of the river is : 

1. 10 km/hr

2. 8 km/hr

3. 6 km/hr

4. 4 km/hr