A ball is thrown upward with a certain speed. It passes through the same point at 3 seconds and 7 seconds from the start. The maximum height achieved by the ball is

1.  500 m

2.  250 m

3.  125 m

4.  450 m

For the following acceleration versus time graph, the corresponding velocity versus displacement graph is:

1.		2.
3.		4.

A stone falls freely from rest from a height h and it travels a distance of $\frac{9h}{25}$ in the last second. The value of h is:

The initial velocity of a particle is u (at t = 0) and the acceleration f is given by at. Which of the following relation is valid?

1. $v=u+a{t}^2$

2. $v=u+a\frac{t^2}{2}$

3. $v=u+at$

4. v = u

The velocity of a body depends on time according to the equation $v=20+0.1t^2$. The body is undergoing 

1. Uniform acceleration

2. Uniform retardation

3. Non-uniform acceleration

4. Zero acceleration

Which of the following four statements is false?

Two cars A and B are travelling in the same direction with velocities v₁ and v₂ $(v_1>v_2)$. When the car A is at a distance d behind car B, the driver of the car A applied the brake producing uniform retardation a. There will be no collision when-

1. $d<\frac{{(v_1-v_2)}^2}{2a}$

2. $d<\frac{v_1^2-v_2^2}{2a}$

3. $d>\frac{{(v_1-v_2)}^2}{2a}$

4. $d>\frac{v_1^2-v_2^2}{2a}$ 

The displacement of a particle is given by $y=a+bt+c{t}^2-d{t}^4$. The initial velocity and acceleration are respectively 

1. $b,-4d$

2. $-b,2c$

3. $b,2c$

4. $2c,-4d$ 

Two trains travelling on the same track are approaching each other with equal speeds of 40 m/s. The drivers of the trains begin to decelerate simultaneously when they are just 2.0 km apart. Assuming the decelerations to be uniform and equal, the value of the deceleration to barely avoid collision should be 

1. 11.8 m/s²

2. 11.0 m/s²

3. 1.6 m/s²

4. 0.8 m/s²

The displacement of a particle starting from rest (at t = 0) is given by $s=6t^2-t^3$. The time in seconds at which the particle will attain zero velocity again, is  

(1) 2

(2) 4

(3) 6

(4) 8