Question 3 :
When a net force acts on an object, the object will be accelerated in the direction of the force with an acceleration proportional to

Question 4 :
If the action and reaction forces are always equal in magnitude, then these forces

Question 5 :
In a uniform linear motion which of the following quantities remains zero?

Question 6 :
Read the following statements and state whether they are True or False:<br/>i) If $u$ and $a$&#160;<span>both are negative, motion is only retarded.<br/></span>ii) If $u$ is negative but $a$&#160;<span>is positive<span>, then&#160;displacement of the particle can never be positive.<br/>iii) If u is positive but $a$ is negative particle comes to rest for a moment at some time but if $u$ is negative and $a$&#160;<span>positive it never comes to rest.</span></span></span>

Question 7 :
The wall of your classroom is in a state of -

Question 10 :
The product of the time period of a sound wave and its frequency is equal to:

Question 11 :
Loud sound can travel a __________ distance as it is associated with_________ energy.

Question 12 :
Statement 1: Loudness is the characteristic of a musical sound by which a loud sound can be distinguished from a faint sound.<br/>Statement 2: Echo is always produced when sound is incident on the hard and polished surface.

Question 13 :
Work done by the gravitational force on a body&#160;of mass $m$ moving on a smooth horizontal&#160;surface through a distance $s$ is: (Given acceleration due to gravity $=g$):

Question 14 :
A car is being driven at a constant speed of $5\ m/s$&nbsp; by a force of ${3\times 10^8}\ N$. It takes $2$ minutes to reach&nbsp;its destination. What is the work done?

Question 15 :
What is the work done by a force of 2 N in displacing a body by 2 m in the direction of the force?

Question 17 :
The force of gravitation between two bodies does not depend upon

Question 18 :
Two particles of mass $m_1$ and $M_2$, approach each other due to their mutual gravitational attraction only. Then<br>

Question 19 :
<div>Two persons having mass $50$ kg each, are standing such that their centre of gravities are $1\ m$ apart. Calculate the force of gravitation between them. <br/></div><div>(Take $G = 6.67\times 10^{-11}N\ m^{2} kg^{-2}$, mass of earth $M = 6\times 10^{24} kg$, Radius of earth $R = 6.4\times 10^{6}m$)</div>

Question 20 :
How the gravitational constant will change if a brass plate is introduced between two bodies?<span><br></span>

Question 21 :
A body of mass $10 \ kg$ is thrown up with a velocity $98 ms^{-1}$. Simultaneously another is dropped from a tower. After 2 seconds their momenta are found to be same in magnitude. Then the mass of the freely falling body is&#160;