Given below are two statements: 

Assertion (A):	A body is momentarily at rest when it reverses the direction of motion.
Reason (R):	A body cannot have acceleration if its velocity is zero at a given instant of time.

1.	Both (A) and (R) are true and (R) is the correct explanation of (A).
2.	Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.	(A) is true but (R) is false.
4.	(A) is false but (R) is true.

The position (x) of a particle moving along x-axis varies with time (t) as $\mathrm{x}={\mathrm{t}}^2-4\mathrm{t}+5$. The particle turns around at

1. t=1 s

2. t=2 s

3. t=3 s

4. t=4 s

The velocity (v) of a particle varies with position (x) as shown in the graph. Its acceleration when x=4 m will be

1. $-8 \mathrm{m}/{\mathrm{s}}^2$

2. $8 \mathrm{m}/{\mathrm{s}}^2$

3. $2 \mathrm{m}/{\mathrm{s}}^2$

4. $-2 m/s^2$

The acceleration time graph of a particle moving along a straight line is shown in the figure. The time taken by the particle to acquire its initial velocity is?

1. 4 s
2. 8 s
3. 10 s
4. 5 s

Position of a particle moving on a straight line is given by $\mathrm{x}=2{\mathrm{t}}^2-6\mathrm{t}$. The distance travelled by the particle in first four seconds is

1. 3 m

2. 17 m

3. 22 m

4. 28 m

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

1. 2 m

2. 4 m

3. 6 m

4. 8 m

The acceleration-time graph of a particle moving along a straight line is given. At what time, the speed of a particle becomes equal to its initial speed?

      
1. 10 s
2. 8 s
3. 6 s
4. 4 s

The acceleration (a) versus time (t) graph of a particle moving along a straight line is shown in the given figure. The particle starts from rest at t=0. The velocity of the particle is maximum at
             

1. t=2 s
2. t=4 s
3. t=6 s
4. t=3 s

A graph between square of speed with time t for a particle moving on a straight line. The acceleration of the particle at t=1 s is

1. $1 \mathrm{m}/{\mathrm{s}}^2$

2. $1.5 \mathrm{m}/{\mathrm{s}}^2$

3. $2.0 \mathrm{m}/{\mathrm{s}}^2$

4. $2.5 \mathrm{m}/{\mathrm{s}}^2$

A body has an initial velocity of 3 m/s and has an acceleration of 1 m/s² normal to the direction of the initial velocity. Then its velocity 4 seconds after the start is:

(1) 7 m/s along the direction of initial velocity

(2) 7 m/s along the normal to the direction of initial velocity

(3) 7 m/s mid-way between the two directions

(4) 5 m/s at an angle of tan^–1 (4/3) with the direction of initial velocity