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Physics Class 9 notes for kpk chapter 1 pdf download physical quantities and measurement. PHYSICAL QUANTITIES AND MEASUREMENT Q.1      What is physics? Also, describe its important branches? PHYSICS :>  The branch of science which deals with the study of properties, energy, and their mutual relationship is called physics” Some important branches of physics are given below 1.       Mechanics:- It deals with the motion of bodies under the action of the force. 2.       Heat and thermodynamics:- It deals with the study of nature, properties. and uses of heat energy. And also deals with the transformation of heat energy from one to another form. 3.       Optics:-  it deals with the prorogation, reflection, refraction, dispersion, and wave properties of light. 4.       Electricity and magnetism:-  it deals with the study of charges at rest as well as in motion. 5.       Atomic physics:- it deals with the structure and properties of an individual atom. 6.       Nucleus physics:-  it deals

What is kinematics? Also, define rest and motion? Ans.      Kinematics:- the branch of physics which deals with the study of the motion of bodies without reference to force is called kinematics.              Rest:- if a body does not change its position with respect to its surrounding then the body is called in a state of rest. For example, a boy is setting in his chair in his classroom .then he does not change his position with respect to his surrounding and we say that boy is in a state of rest. Motion: – if a body changes its position with respect to its surrounding then the body is called in a state of motion. For example, a cyclist changes his position every moment with respect to his surrounding then we say that cyclist is in state of motion. Q.2 discuss types of motion with examples? Ans.     There are three types of motion that are given below. Translator motion:-   That type of motion in which every particle of a body moves parallel to each other along any path is known as tra

Physics IX Notes Chapter 3 Dynamic Q.1 Define and explain force? Ans. a force:- an agent which moves or tends to move a stationary body stops or tends to stop a moving body or tends to change the speed or direction of moving body is known as force. Force is a vector quantity and its unit is Newton. One Newton is that force that moves a body of one kg with the acceleration of 1m/sec2. Q.2 state and explain or Newton 1st law of motion? Ans. Newton’s 1st law:- this law states that in the absence of any external force a body in rest will always remain in rest and a body in motion will always continue its motion in a straight line with uniform speed.             Explanation:- this law has two parts which are explained below. In the 1st part, it is stated that in the absence of any external force a stationary body will always be at rest, for example, a book is laying on the table so it will remain stationary and will not change it’s by itself unless someone moves it by applying a force. In 2

Physics IX Notes Chapter 4 TURNING EFFECT OF FORCES Q.1 explains the various forces acting on a body? Ans. (a) in the earth gravitation field, the attracts everything towards its centre the gravitational force acting on each particle of body is parallel as shown in fig (a) (a)    In figure (b) two a block is shown on a table. Two forces are acting on it. Its weight “w” in a downward direction while the normal force of the table on the block in an upward direction, these forces have some line of action and balance each other. (b)   In figure “c” two forces “p” and “Q” are shown which are acting at points “A” and “B” these forces are known as parallel forces. (c)    In figure (d) two forces “l” and “m” are shown which are acting at points “c” and “D” these forces are known as “ anti-parallel” forces. Q.2 Explain the addition of forces in detail: Ans:- force is a vector quantity and forces can be added with each other by vector algebra. The vector we get after the addition is known as th

Q.1   state and explain Newton’s law of gravitation? Ans. Newton’s of universal gravitation:-  this law states that in this universe Avery two bodies attract each other with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance b/w them. Explanation :- consider two bodies a and b as shown in figure let their masses are m1and m2 respectively and the distance b/w they is “r” then according to Newton’s law of gravitation the force of attraction :f: is given as:- F m1m2 …………………………… (i) F   1/r2 ……………..(ii)                 Combining eq (i) and eq (ii) we get. F m1m2 1/r2 F  m1m2 1/r2…………….(iii) Eq (iii) is the mathematical form of Newton’s law of gravitation. Where “G” is gravitational constant and its value is equal to 6.673 x 10-11= N.m2 /kg2 Q.2 using the law of universal gravitation find the mass of earth? Ans.  we can find the mass of earth “Me” by using universal gravitation by following method suppose we have a

Q.2 Define energy? Also, give its different types?  Ans. energy:- The ability of a body to do work is known as the energy it’s unit the same as work that is joules.   forms of energy:- different types of energy are given below. (1)    Chemical energy:- energy which is obtained during chemical reaction and burning of substances is called chemical energy e.g. burning of wood, coal and petroleum etc. (2)    Nuclear energy: – that type of energy which is produced during a nuclear reaction is known as nuclear energy for an example process of nuclear fission. (3)    Radicand energy: = the energy of electromagnetic waves is called radiant energy. For example radio waves microwaves x – rays etc have radiant energy. (4)    Electrical energy:- that type of energy with the help of which we can operate different electrical equipment is called electrical energy. (5)    Internal energy: – the energy of atoms and molecules which is usually in the formula kinetic energy and potential energy is call