Ideal Science Academy Unit No 1 (1) Define Physics? d eals with the study of matter and energy and their mutual relationship (2) Ans: The branch of science which deals is called Physics. (2) Write names of the branches of Physics? Ans: (1) Mechanics
(2) Heat & Thermodynamics (3) Sound (4) Light
(5) Electromagnetism (6) Atomic and Molecular Physics (7) Nuclear Physics (8) Plasma Physics (9) Solid Physics Which scientist invented a toy working on steam? Ans: The famous scientist of Alexandria “Hero” invented the toy working on steam. (3) Define Plasma? Ans: The state of matter at a very ver y high temperature comprising the ions and electrons is called pla sma. (4) Name the branches of physics overlapping the other branches of science? Ans: (1) Astrophysics
(2) Geophysics
(3) Biophysics
(7) Differentiate between observation and experiment? Ans:
To collect facts about the natural phenomena phe nomena is called observation.
While Experiment is the organized process which is performed to test the truth of hypothesis. (10) What is the best replacement of coal for the production of energy? Ans:
Solar energy and the atomic energy are two best replacements of coal for the production of energy.
(11) How much energy could be produced from Uranium? Ans: Energy obtained by the breaking up of one kilogram of Uranium is equal to the energy obtained from the burning of 3 million kg of coal. (12) In which state most of our universe exists?
p lasma. Ans: Most of our universe is in the state of plasma.
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(13) What is the work of Nichole Oresme in Physics? Prepared by:
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Ideal Science Academy geometr y. Ans: He studied in the change in velocity with the help of geometry. (14) Who studied the freely falling bodies? Ans: Galileo studied the freely falling bodies 15)Explain the theory of mass and energy? Ans: th In 20 century Einstein told that the mass and energy are, in fact, forms of each other. other. (16)What was the major work of Dr. Abdus Salam? Ans: in 1979 Dr. Abdus Salam gave the theory of unification in which he explained that weak nuclear force and electromagnetic force are of same form.
MEASUREMENTS Why a standard unit is need to measure a quantity correctly. Ans:
Various units have been in use in different times in different parts of the world. The fast means of communication systems systems have changed the world into a global village. Due to this reason an international system of units for mutual business became essential. The eleventh general conference of weights and measures recommended that all the countries of world should adopted a system of same kind of standard units, consisting of seven base units known as international system of units (SI) and derived units. Q: What is meant by base and derived units? Give three examples of derived units and explain how they are derived from base units. Ans: Base Units: The units of base quantities are called base units. Examples: Kilogram (kg), meter (m), second (s), Ampere (A) Derived Units: The units of derived quantities which are derived from base units are called derived units. Examples:
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Ideal Science Academy 2
Unit of Area: m . 3 Unit of Volume: m -3 Unit of Density: Kg m Unit of speed: meter per second (ms-1), Unit of weight: Newton Unit of force: Newton, Unit of Pressure: Pascal Q : How they are derived from base units: These units are obtained by multiplication, division or both of base units. units. Unit of Area: length x breadth Unit of length x unit of breadth Meter x meter mxm 2 :m
Unit of Volume: length x breadth x height Unit of length x unit of breadth x unit of height Meter x meter x meter mxmxm 3 :m Unit of Density: Mass Volume Unit of mass Unit of volume Q: What is the number of base units in System International (SI)? Ans. There are seven base units which are given below Number Physical Physical Quantity Unit Unit Symbol 1. Length Meter (m 2. Mass Kilogram(kg 3. Time Seconds (s 4. Electric current Ampere( A 5. Temperature Kelvin( K 6. Intensity of light Candela(cd 7. Amount of substance(Mo substance(Mole le mol
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Ideal Science Academy Q: Where multiples multiples and sub-multiples of units are used? Describe Describe some standard standard prefaces which are internation internationally ally used.
Ans. Multiples and sub-multiples of units are used to make very large and very small mathematical calculations easier. The multiples and sub-multiples are obtained by multiplying or dividing with ten or power of tens. The terms used internationally for the multiples and sub-multiples for different units are called prefixes.
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Q: What is the use of vernier calipers? What is meant by its vernier constant? Ans. A vernier calliper can be used to measure lengths accurately up to one tenth of a millimeter. Least Count/Vernier Constant The minimum length which can be measured accurately with the help of vernier scale or vernier calipers is called least count. Least count of vernier calliper is 1/10 mm or 0.1 cm which is also called vernier constant. Q: Explain the statement “A micrometer screw gauge measures more accurately than a vernier caliper”? Ans. Least Count: The minimum length which can be measured accurately is called least count of any measuring device.
The least count of micrometer screw gauge is 0.01 mm and that of Vernier calliper is 0.1. mm. So a micrometer screw gauge measures more accurately than a vernier calliper.
Unit # 2
Kinematics
Define Mechanics and its types. The branch of physics, which deals with the study of motion of bodies, bod ies, is called Mechanics. It has two types: Prepared by:
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Ideal Science Academy I) Kinematics ii) Dynamics Define Types of Mechanics. Kinematics:
It is study of motion of bodies without reference o f force and mass. Dynamics:
It is study of motion of bodies with reference o f force and mass. Define Rest If a body does not change chan ge its position with respect to some observers then it is said to be in the state of rest. Define Motion If a body is changing its position p osition with respect of some observers then it is said to be in the state of motion. Name the types of motion a. Translatory Motion
b. Linear motion c. Circular motion d. Random motion e. Rotatory Motion f. Vibratory Motion What is the motion butterfly? Executed by Flight of butterfly is irregular motion. Therefore its motion is called random motion. What is type of motion of free falling bodies? Freely falling bodies move downward in straight direction under the force of gravity. Therefore their motion
is called linear motion. What is the type of motion of a man moving in circular track? His motion is circulatory motion. Define Distance The path between two points po ints is called distance. It is scalar quantity. Define Displacement The shortest distance between two points is called displacement. It is a vector quantity. What are Scalar and Vector Quantities? Scalars are those quantities which are described by a number with suitable unit un it without direction.
Vectors are those quantities which can be described by a number with suitable unit and with direction. 5
Define Velocity The distance covered by a body in a unit time in a particular direction is called velocity.”
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Ideal Science Academy OR The rate of change of displacement is called velocity. It is denoted b y v. It is a vector quantity. 1.
Positive
Acceleration
If the velocity continuously increases then the acceleration will be positive. 2.
Negative
acceleration
If the velocity continuously decreases then the acceleration will be negative. Define Uniform Speed If a body covers an equal distance in equal interval of time in a particular direction, particular direction, the body is said to be
uniform Velocity. Define variable velocity If a body does not cover an equal distance in equal interval of time
in a particular direction, the body bod y is said to be in variable velocity. Define relative velocity When two bodies are in motion then the velocity of one body
relative to other is called relative velocity. Define Instantaneous velocity The velocity of a body at any instance of time is called
instantaneous velocity. Define Average velocity Average velocity of a body can be obtained by dividing the total displacement with total time taken.
Vav = Displacement/Time = d/t Can a body moving with certain velocity in the direction of East can have acceleration in the direction of West? Ans:
Yes, if the velocity of the body decreases, then it will have acceleration in the opposite direction, that is, in the direction of west. Does speedometer of a car measures its velocity? It measures only speed but not velocity. Define Acceleration. The rate of change of velocity is called acceleration. It is denoted by “a”. It is a vector quantity. Define Uniform Acceleration If velocity of a body is changing c hanging equally in equal intervals of times then its acceleration will be uniform.
6 Define Variable Acceleration e g a If velocity of a body is not changing equally in equal intervals of times then its acceleration will be variable. P
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Ideal Science Academy Define Average Acceleration The average acceleration can be obtained by dividing total change in velocity with total time taken.
aav = Change in Velocity/Total Time =(Vf – Vi)t – Vi)t Define Gravitational Acceleration The acceleration of freely falling bodies is c alled gravitational acceleration. It is denoted denoted by g. Its value -2
is 10 meter per second per second (10 ms ) 2.
3.
4.
A body is thrown vertically upward. What is gravitational acceleration? Ans : -2 It is 10 meter per second per second (10 ms ) What is acceleration of a body moving movin g with uniform velocity? Ans : The acceleration will be 0. What consideration should be kept in mind while using equation of motion for free falling bodies? • Initial velocity velocity should be taken as zero. • Acceleration will be taken as (g) instead o f (a)
Define Speed The distance covered in unit time is called speed.
Speed = Distance/Time v = S/t -1
The unit of speed is meter per second (ms ) or m/s 5.
6.
7.
8.
9.
10.
11.
Can a body moving at a constant speed have acceleration? Yes, if it is moving in circular path, it can have acceleration. A body is moving with uniform velocity, what will be its acceleration? Its acceleration will be zero. A body is moving with a uniform speed. Will its velocity be uniform? Yes, if it moves in straight line and does not change its direction. Can a body moving with a certain velocity in direction of East, East , have Acceleration in the direction of West? Yes, if its velocity will decrease, it has acceleration in the direction of west. Does speedometer a car measure its velocity? No, it only measures the speed. Why a stone and a piece of paper when dropped from the same height, reach the ground at the same time. Because both have same gravitational acceleration. What type of change will occur in three equations of motion under the action of gravity? Acceleration (a) will be replaced with gravitational acceleration (g) in all equations. And distance (s) will be changed in to height (h).
7
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Ideal Science Academy Three equations of motion are three equations equ ations of motion under the action of gravity are Vf = Vi + at
Vf =Vi+gt 2
h=Vit+1/2
2
2gh = Vf – V – Vi
S = Vi t + 1/2 at 2
2aS = Vf – V – Vi
2
gt
2
2
Long Questions: Describe the different types of motion in detail? Motions of bodies are of three types: i) Translatory Motion: -
A motion in which each particle of a body has exactly same motion is called Translatory Motion. It may be of many kinds for examples: a. Linear Motion: If a body moves in straight line its motion is called linear motion. e.g. motion of free falling bodies, a man walking on a straight path b. Circular Motion: If a body moves in a circle its motion is called circular motion. e.g. motion of stone attached to thread and whirled. c. Random Motion: If a body moves in irregular manner its motion is called random motion. e.g. motion of butterfly. ii) Rotatory Motion: Motion
is
said
to
Rotatory,
when
the
object
rotates
on
its
own
axis.
Examples: Rotatory motion of a planets on its ax is, wheels of a vehicles, spinning top, top , ceiling fan etc. iii) Vibratory Motion: -
When a body moves to and fro about a point and repeats its motion then its motion is called vibratory motion. e.g. Motion of simple Pendulum, motion of tuning fork, A ruler. Place one inch of it on a desk, and the other 11 off the desk. Flick the end off the desk and watch it vibrate.
Motion Graphs
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For body body moving at constant velocity:
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Ideal Science Academy The graph of straight line parallel to the X axis shows that the body is moving with constant velocity a)
Derivation of Equation of Motion (Graphically)
First Equation of Motion Consider an object moving with a uniform velocity u in a straight line. Let it be, given a uniform acceleration at time, t = 0 when its initial velocity is V i. As a result of the acceleration, its velocity increases to V f (final velocity) in time t and s is the distance covered by the object in time t. The figure shows the velocity-time graph of the motion of the object. Slope of the V f - t graph gives the acceleration of the moving object. Thus, acceleration = slope = AB = BC/AC
Where BD=Vf, CD=Vi, AC= OD=t BC=BD-CD (Average,acceleration(aav)= Slope=AB= Vf - Vi/
ChangeinVelocity/time)
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t
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Ideal Science Academy a = Vf - Vi/
t
Vf – – Vi = at Vf = Vi + at ........................................................(1)
Second Equation of Motion Let Vi be the initial velocity of a n object and 'a' the acceleration produced in the body. The distance travelled s in time t is given by the area enclosed by the velocity-time graph for the time interval 0 to t. Distance travelled Total aera of OABD=
S = area of the trapezium ABDO
area of rectangle ACDO + area of ΔABC Î ”ABC = OD x OA +
Where,
OA=VI, OD=t,
⁄ (BC x AC)
BC=BD-CD,
AC=t, BD=Vf, CD=Vi
= t x V i + ⁄ (Vf - Vi ) x t = Vi t +
⁄
(Vf - Vi ) x t
(vf = Vi + at I eqn of motion; vf - vi = at) S = Vi t + 1/2at x t 2
S = Vt + 1/2at .
Third Equation of Motion Let 'u' be the initial velocity of an object and a be the acceleration produced in the body. The distance travelled’s’ in time’t’ is given by the area enclosed by the v - t graph.
S= area of the trapezium OABD.
= 1/2 (OA + BD) x AC
where OA=Vi, BD= Vf, AC=OD=t
0 1
= 1/2 (Vi + Vf )t )t ....(1) But we know that a =( V f - Vi
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)t
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Ideal Science Academy Or t = (Vf - Vi )a Substituting the value of t in eq. (1) we get, s = 1/2 (Vi + Vf )( )( Vf − Vi)a = 1/2 (Vf + Vi)( Vf − Vi)a 2as = (V f + Vi) ( Vf - Vi ) 2
(Vf + Vi)( Vf - Vi) = 2as 2
v - Vi
2
2
[using the identity a - b = (a + b) (a - b)]
= 2as........... Third Equation of Motion
Acceleration Due To Gravity Or Free Falling Objects
“Galileo was the the first scientist to observe that, neglecting the effect of air resistance, all bodies in free-fall close 2
to the Earth’s surface accelerate vertically downwards with the same a cceleration: namely 9.8 m/s ″ Example If a ball is thrown vertically upward, it rises to a particular height and then falls back to the ground. However this is due to the attraction of the earth which pulls the object towards the ground”
Characteristic Of Free Falling Bodies
1. When a body is thrown vertically upward, its velocity continuously decreases and become zero at a particular height During this motion the value of acceleration is negative and Vf is equal to zero 2
(a = -9.8m/s , Vf = 0). 2. When a body falls back to the ground , its velocity continuously increases and become maximum at a 2
particular height During this motion the value of acceleration is positive and Vi is equal to zero (a = 9.8m/s , Vi = 0). 2
3. Acceleration due to gravity is denoted by a and its value is 9.8m/s . 4. Equation of motion for the free-falling bodies be written as, Vf = Vi + gt h = Vi t + 1/2 gt 2
2gh = Vf – V – Vi
2
2
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Ideal Science Academy Chapter Chapter # 3
D ynamics ynami cs
1. FORCE The Force is an agent which produces or tends to produce a motion in a body or it stops or tends to stop the motion of a body. In simple words we can also say that force is an agent which changes or tends to change the state of an
object. UNIT
The unit of a Force in M.K.S M. K.S System is Newton 2. MASS
The quantity of matter contained in a body is called mass. It is a scalar quantity. quan tity. FORMULA F = ma m = F/a UNIT The unit of mass in M.K.S S ystem is Kilogram (kg). 3. WEIGHT
The force with which earth attracts other bodies towards its centre is c alled weight. It is a vector quantity. qu antity. FORMULA;
W = mg
UNIT The unit of weight in M.K.S System is Newton (N). INERTIA Definition
“Inertia is the tendency of a bod y to resist a change in its state.” Examples
Cover a glass with a post card and place a coin on it. Now strike the post card swiftly with the nail of your finger. If the stroke has been made correctly, the postcard will be thrown away and the coin will drop in the glass. 2 1 e g a P
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Ideal Science Academy If a moving bus stops suddenly, the passenger standing in it feels a jerk in the forward direction. As a result he may fall. It is due to the fact that the lower part of the standing passengers comes to rest as the bus stops. But the upper portion remains in motion due to inertia.
Difference between Mass and Weight Mass 1. The quantity of matter present in a body is called mass. 2. The mass of a body remains constant everywhere and does not change by change in altitude. 3. It is a scalar quantity. 4. Mass can be determined by a physical balance.
Weight 1. The force with which the earth attracts a body towards its centre is called the weight of the body. 2. The weight of a bod y is not constant. It is changed by b y altitude. 3. Weight is always directed towards the center of the earth. So it is a vector quantity. 4. Weight can be determined by only a spring balance.
MOMENTUM “The quantity or quality of motion is called momentum and it is denoted by b y P” MATHEMATICAL DEFINITION
“It is the product of mass and velocity.” MATHEMATICAL REPRESENTATION P = mV where: p is the momentum m is the mass v the velocity
LAW OF MOTIONS 3 1
Newton formulated three laws of motion in his book.
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NEWTON FIRST LAW OF MOTIONS Prepared by:
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Ideal Science Academy Newton’s first law of motion is also also known as the Law of Inertia. STATEMENT
“Every body continues its state of rest or uniform motion in a straight line until it is acted upon by an external or
unbalance force to change its state of rest or uniform motion”. EXPLANATION
This law consists of a two parts (a) When body is at rest (b) When body is moving with uniform velocity (a). When a body is at rest Newton’s Law states that when a body is at rest, it continues its rest rest unless we apply a force on it. When we apply a force, it changes its state of o f rest and starts moving along a straight line. (b) When body is moving with a uniform velocity Newton’s Law states that when a body is moving, it moves in a straight line with uniform uniform velocity, but when we apply an opposite force, it changes chan ges its state of motion and come to rest. Examples If a bus suddenly starts moving, the passengers standing in the bus will fall in the backward direction. d irection. It is due to the reason that the lower part of the passengers which is in contract with the floor of the bus is carried forward by the motion of the bus, but b ut the upper part of the bod y remains at rest due to inertia and so the passengers fall in backward direction. If a bus suddenly stops moving, the passengers passen gers standing in the bus will fall in the forward direction. It is due to the reason that the lower part of the passengers which is in contract with the floor of the bus is stopped with the bus, but the upper part of the body remains moving due to inertia and so the passengers fall in forward direction.
SECOND LAW OF MOTION STATEMENT “When a force acts on an object it produces an acceleration which is directly proportion to the amount of the force and inversely proportional to the product of mass” EXPLANATION
When we push a body with greater force then its velocity increases and change of velocity takes place in the direction of the
4 force. If we apply a certain force F on a mass m, then it moves with certain velocity in the direction of the force. 1 e g a P
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Ideal Science Academy If the force becomes twice then its velocity will also increase two times. In this way if we go on increasing the fore there will be increase in velocity, which will increase the acceleration. DERIVATION
According to the Newton`s Second law of motion when a force acts on an object it produces an acceleration which is directly proportion to the amount of the force. a∝F and inversely proportional to the product of mass a ∝ 1/m Combining both. a ∝ F/m A = constant F/m a = k F/m If the Value of constant K is 1 so, a = F/m or F = ma
THIRD LAW OF MOTION Statement: “To every action there is always an equal and opposite reaction ” EXPLANATION
According to Newton’s Law of Motion, we have: F(action) = – = – F(reaction) F(reaction) The negative (-) sign indicates that the two forces are pa rallel but in the opposite direction. If we co nsider one of the interacting objects as A and the other as B, then according to the third law of motion: F(AB) = – = – F(BA) F(BA) F(AB) represents the force exerted on A and F(BA) is the force exerted on B. Examples
We walk on the ground, we push the ground backward and as a reaction the ground pushes us forward. Due to this reason we are able to move on the ground. Prepared by:
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Ideal Science Academy If a book is placed on the table, it exerts some force on the table, which is equal to the weight of the book. The table as a reaction pushes the book upward. This is the reason that the book is stationary on the table and it does not fall down.
FRICTION Definition The force, which resists the motion of one surface on another surface, is known as friction.
Explanation Suppose a wooden block is placed on a table and a spring balance is attached on it. If we apply a very small force of magnitude F by pulling the spring gradually and increase it, we observe that the block does not move until the applied force has reached a critical value. If F is less then critical value, the block does not move. According to Newton’s Third Law of moti on an opposite force balance the force. T his opposing force is known as the force of frictio n or friction.
CausesofFriction If we see the surface of material bodies through microscope, we observe that they are not smooth. Even the most polished surfaces are uneven. When one surface is placed over another, the elevations of one get interlocked with the depression of the other. Thus they oppose relative motion. The opposition is known as friction.
Factors on which Friction Depends The force of friction depends upon the following factors: 1. Normal Reaction (R) Force of friction is directly proportional to normal reaction (R), which act u pon the body in upward direction
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Ideal Science Academy 2. Nature of Surfaces Force of friction also depends upon the nature of the two surfaces. It is denoted as u and has constant values for every surface. It is different for the two surfaces in contact. Coefficient Of Friction The coefficient of friction is a number which represents the friction between two surfaces. Between two equal surfaces, the coefficient of friction will be the same. The s ymbol usually used for the coefficient of friction is
Greek letter µ , where 0 ≤ µ ≤ 1 . The maximum frictional force (when a body bod y is sliding) is equal to the coefficient of F=µ
friction × the normal reaction force. R Where µ is the coefficient of friction and R is the normal reaction force.
This frictional force, F, will act parallel to the surfaces in contact and in a direction to oppose the motion that is taking/ trying to take place.
Advantages of Friction f orward, we push our 1. We could not walk without the friction between our shoes and the ground. As we try to step forward, foot backward. Friction holds ho lds our shoe to the gr ound, allowing you to walk. 2. Writing with a pencil requires friction. We could no t hold a pencil in our ou r hand without friction. 3. A nail stays in wood due to friction 4. Nut and bold hold due to friction
DISADVANTAGES OF FRICTION –such s uch as a car, boat or airplane – –excess e xcess friction means that extra fuel must be used to power the vehicle. 1. In any type of vehicle – In other words, fuel or energy is wasted because of the friction. amount of energy remains constant. Thus, the energy that is “lost” to 2. The Law of Conservation of Energy states that the amount of friction in trying to move an object is really turned to heat energy. The frict ion of parts rubbing tog ether creates heat. 3. Due to the friction a machine has less efficiency less than 100%. 7 1
4. Due to friction machine catch fire.
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Ideal Science Academy Laws of Friction Statement
The value of limiting friction increases proportionally with the increase in normal reaction. Henc e, liming friction F(s) is directly proportional to the normal reaction. F(s) < R (Here < represents the sign of proportionality don’t’ write it in the examination paper.) => Fs = µ R ……….. (i) u = F(s)/R u is the constant of proportionality, which depends upon the nature of the surfaces of the two surfaces in contact. It is known as the coefficient of friction. It is only a number without any unit. We know that the normal reaction is directly proportional to the weight of the block , therefore, R = W = mg Substituting the value of R in equation equ ation (i) => Fs = µ mg
Rolling Friction
When a body rolls over a surface, the force of friction is called rolling friction. Rolling friction is much less than the sliding friction. This is because the surfaces in contact are v ery much less.
LONG QUESTIONS Question: Explain the Law of Conservation of Mo mentum? This law states that “When two or more bodies collide with one another the total momentum of the
system remains the same, provided no external force a cts upon them.” Explanation: The law of conservation of momentum is a fundamental law of nature, and it states that the total momentum of
an isolated system of objects (which has no interactions with external agents) is constant. One of the consequences of this is that the of any centre of mass system of objects will always continue with the same velocity unless acted on by a force outside the system. Consider two balls of masses m 1 and m2. They are initially moving with velocities u1and u2 in same direction on 8 1 e g a straight line. If u1 > u2, then the balls will collide. Let their velocities v elocities becomes v1 and v2 after collision. a P
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Ideal Science Academy Total momentum of balls before collision =
m1u1 + m2u2
Total momentum of balls after collision =
m1v1 + m2v2
According to Law of conservation of momentum
Total Momentum before collision m1u1 + m2u2
=
Total Momentum after collision
=
m1v1 + m2v2
Question: Define friction and describe the types of friction
Question: What is force of friction? How friction can be reduced? Friction: The force, which resists the motion of one surface on another surface, is known as friction.
Methods to reduce friction: i) Sliding parts should be highly polished to reduc e friction.
ii) Friction of liquids is less than solids. Therefore oil or grease is applied b etween the parts of machinery. iii) Rolling friction is less then sliding friction. Therefore sliding friction should be converted to rolling friction by using ball bearings. iv) Front side of vehicles, aeroplanes and ships are shaped wedge like and pointed so that minimum friction is offered by air. Centripetal Force Definition “The force that causes an object to move along a curve (or a curved path) is called centripetal force.”
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Ideal Science Academy Mathematical Expression We know that the magnitude of centripetal acceleration of a body in a uniform circular motions is directly proportional to the square of velocity and inversely proportional to the radius of the path Therefore, 2
a(c) ∝v
a(c) ∝ 1/r Combining both the equations: 2
a(c) ∝ v /r From Newton’s Second Law of Motion: F = ma =>
2
F(c) = mv /r
Where, Fc = Centripetal Force
m = Mass of object
v = Velocity of object
r = Radius of the curved path
Banking of the roads Factors on which Fc Depends: Fc depends upon the following factors: Increase in the mass will increases Fc. It increases with the square of velocity. It decreases with the increase in radius of the curved path.
When a car takes
Examples The centripetal force required by natural planets to move constantly round a circle is provided by the gravitational force of the sun.
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Ideal Science Academy If a stone tied to a string is whirled in a circle, the required centripetal force is supplied to it by our hand. As a reaction the stone exerts an equal force which is felt by our hand.
The pilot while turning his aero plane tilts one wing in the upward direction so that the air pressure may provide the required suitable Fc.
Centrifugal Force Definition
“A force supposed to act outward on a body moving in a curve is known as centrifugal force.” Explanation Centrifugal force is actually a reaction to the c entripetal force. It is a well-known fact that Fc is directed towards the centre of the circle, so the centrifugal force, which is a force of reaction, is directed away from the centre of the circle or the curved path.
Examples If a stone is tied to one end of a string and it is moved round a circle, then the force exerted ex erted on the string on outward direction is called centrifugal force.
The aeroplane moving in a circle exerts force in a direction opposite to the pressure of air. When a train rounds a curve, the centrifugal force is also exerted on the track.
Two long question learn from book,
a) Find acceleration and tention in string when objects move vertically? b) Find Tention and acceleration when one object moves vertically and other one horizontally? 1 2 e g a P
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