A car is moving along a straight line, say \(OP\) in the figure. It moves from \(O\) to \(P\) in \(18\) s and returns from \(P\) to \(Q\) in \(6.0\) s. The average velocity and average speed of the car in going from \(O\) to \(P\) and back to \(Q\) respectively are:

1. \(10\) m/s & \(10\) m/s

2. \(20\) m/s & \(30\) m/s 

3. \(20\) m/s & \(20\) m/s

4. \(10\) m/s & \(20\) m/s

The position of an object moving along \(x\)-axis is given by \(x=a+bt^2\), where \(a=8.5\) m, \(b=2.5 \text{ ms}^{-2}\) and \(t\) is measured in seconds. Its average velocity between \(t=2.0\) s and \(t=4.0\) s is:

Which of the following does not represent the equation of motion for constant acceleration?

A ball is thrown vertically upwards with a velocity of \(20\) m/s from the top of a multistorey building. The height of the point from where the ball is thrown is \(25.0\) m from the ground. How long will it be before the ball hits the ground?
(Take \(g=10\) ms^–2.)
1. \(3\) s
2. \(2\) s
3. \(5\) s
4. \(20\) s

When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on the initial velocity \({v_0}\) and the braking capacity, or deceleration, \(-a\) that is caused by the braking. Expression for stopping distance of a vehicle in terms of \({v_0}\) and \(a\) is:

You can measure your reaction time by a simple experiment. Take a ruler and ask your friend to drop it vertically through the gap between your thumb and forefinger (figure shown below). After you catch it if the distance d travelled by the ruler is \(21.0\) cm, your reaction time is:

Galileo’s law of odd numbers: The distances traversed, during equal intervals of time, by a body falling from rest, stand to one another in the ratio:
 

A train is moving in south with a speed of 90 ${\mathrm{kmh}}^{-1}$. The velocity of ground with respect to the train is:

1.  0 ${\mathrm{ms}}^{-1}$

2.  -25 ${\mathrm{ms}}^{-1}$

3.  25 ${\mathrm{ms}}^{-1}$

4.  -40 ${\mathrm{ms}}^{-1}$

Two parallel rail tracks run north-south. Train A moves north with a speed of 54 ${\mathrm{kmh}}^{-1}$, and train B moves south with a speed of 90 ${\mathrm{kmh}}^{-1}$. The magnitude of the velocity of B with respect to A is:

1.  40 ${\mathrm{ms}}^{-1}$

2.  0 ${\mathrm{ms}}^{-1}$

3.  25 ${\mathrm{ms}}^{-1}$

4.  15 ${\mathrm{ms}}^{-1}$