Equation of displacement for any particle is $s=3t^3+7t^2+14t+8m$. Its acceleration at time t = 1 sec is 

1. 10 m/s²

2. 16 m/s²

3. 25 m/s²

4. 32 m/s²  

The position of a particle moving along the x-axis at certain times is given below :

Which of the following describes the motion correctly?  

(1) Uniform, accelerated

(2) Uniform, decelerated

(3) Non-uniform, accelerated

(4) There is not enough data for generalization

Consider the acceleration, velocity and displacement of a tennis ball as it falls to the ground and bounces back. Directions of which of these changes in the process ?

1. Velocity only

2. Displacement and velocity

3. Acceleration, velocity and displacement

4. Displacement and acceleration

The displacement of a particle, moving in a straight line, is given by $s=2t^2+2t+4$ where s is in metres and t in seconds. The acceleration of the particle is 

(1) 2 m/s²

(2) 4 m/s²

(3) 6 m/s²

(4) 8 m/s²

The velocity of a bullet is reduced from 200m/s to 100m/s while travelling through a wooden block of thickness 10cm. The retardation, assuming it to be uniform, will be  

(1) $10\times {10}^4$ m/s²

(2) $12\times {10}^4$ m/s²

(3) $13.5\times {10}^4$ m/s²

(4) $15\times {10}^4$ m/s² 

A particle starts from rest, accelerates at 2 m/s² for 10s and then goes for constant speed for 30s and then decelerates at 4 m/s² till it stops. What is the distance travelled by it?

(1) 750 m

(2) 800 m

(3) 700 m

(4) 850 m

A car, moving with a speed of 50 km/hr, can be stopped by brakes after at least 6m. If the same car is moving at a speed of 100 km/hr, the minimum stopping distance is 

(1) 6m

(2) 12m

(3) 18m

(4) 24m  

A student is standing at a distance of 50 metres from the bus. As soon as the bus begins its motion with an acceleration of 1 ms^–2, the student starts running towards the bus with a uniform velocity u. Assuming the motion to be along a straight road, the minimum value of u, so that the student is able to catch the bus is:

1. 5 ms^–1

2. 8 ms^–1

3. 10 ms^–1

4. 12 ms^–1

A body A moves with a uniform acceleration a and zero initial velocity. Another body B, starts from the same point moves in the same direction with a constant velocity v. The two bodies meet after a time t. The value of t is 

1. $\frac{2v}{a}$

2. $\frac{v}{a}$

3. $\frac{v}{2a}$

4. $\sqrt{\frac{v}{2a}}$ 

A particle moves along X-axis in such a way that its coordinate X varies with time t according to the equation $x=(2-5t+6t^2)m$. The initial velocity of the particle is 

(1) –5 m/s

(2) 6 m/s

(3) –3 m/s

(4) 3 m/s