{"id":19323,"date":"2023-02-06T11:16:26","date_gmt":"2023-02-06T05:46:26","guid":{"rendered":"https:\/\/icsesolutions.com\/?p=19323"},"modified":"2023-02-07T10:06:49","modified_gmt":"2023-02-07T04:36:49","slug":"frank-icse-solutions-class-9-physics-laws-motion","status":"publish","type":"post","link":"https:\/\/icsesolutions.com\/frank-icse-solutions-class-9-physics-laws-motion\/","title":{"rendered":"Frank ICSE Solutions for Class 9 Physics – Laws of Motion"},"content":{"rendered":"
PAGE NO: 113<\/strong><\/span> Solution 2:<\/strong><\/span> Solution 3:<\/strong><\/span> Solution 4:<\/strong><\/span> Solution 5:<\/strong><\/span> Solution 6:<\/strong><\/span> Solution 7:<\/strong><\/span> Solution 8:<\/strong><\/span> Solution 9:<\/strong><\/span> Solution 10:<\/strong><\/span> Solution 11:<\/strong><\/span> Solution 12:<\/strong><\/span> Solution 13:<\/strong><\/span> Solution 14:<\/strong><\/span> Solution 15:<\/strong><\/span> Solution 16:<\/strong><\/span> Solution 17:<\/strong><\/span> Solution 18:<\/strong><\/span> Solution 19:<\/strong><\/span> Solution 20:<\/strong><\/span> Solution 21:<\/strong><\/span> Solution 22:<\/strong><\/span> Solution 23:<\/strong><\/span> Solution 24:<\/strong><\/span> Solution 25:<\/strong><\/span> Solution 26:<\/strong><\/span> Solution 27:<\/strong><\/span> Solution 28:<\/strong><\/span> Solution 29:<\/strong><\/span> Solution 30:<\/strong><\/span> Solution 31:<\/strong><\/span> Solution 32:<\/strong><\/span> Solution 33:<\/strong><\/span> Solution 34:<\/strong><\/span> PAGE NO : 114<\/strong><\/span> Solution 36:<\/strong><\/span> Solution 37:<\/strong><\/span> Solution 38:<\/strong><\/span> Solution 39:<\/strong><\/span> Solution 40:<\/strong><\/span> Solution 41:<\/strong><\/span> Solution 42:<\/strong><\/span> PAGE NO: 125<\/strong><\/span> Solution 2:<\/strong><\/span> Solution 3:<\/strong><\/span> Solution 4:<\/strong><\/span> Solution 5:<\/strong><\/span> Solution 6:<\/strong><\/span> Solution 7:<\/strong><\/span> Solution 8:<\/strong><\/span> Solution 9:<\/strong><\/span> Solution 10:<\/strong><\/span> Solution 11:<\/strong><\/span> Solution 12:<\/strong><\/span> Solution 13:<\/strong><\/span> Solution 14:<\/strong><\/span> Solution 15:<\/strong><\/span> Solution 16:<\/strong><\/span> Solution 17:<\/strong><\/span> Solution 18:<\/strong><\/span>
\nSolution 1:<\/strong><\/span>
\nThe property by which a body neither changes its present state of rest or of uniform motion in a straight line nor tends to change the present state is known as inertia.<\/p>\n
\nA book lying on a table will remain placed at table unless it is displaced by some external force. This is an example of inertia of rest.
\nA ball rolling on the ground will continue to roll unless the external force , the force of friction between the ball and the ground stops it.<\/p>\n
\nThe greater is the MASS , the greater is the inertia of the object<\/p>\n
\nAn object possess two kind of inertia, inertia of rest and inertia of motion.A book lying on a table will remain placed at table unless it is displaced by some external force. This is an example of inertia of rest.
\nA ball rolling on the ground will continue to roll unless the external force , the force of friction between the ball and the ground stops it.<\/p>\n
\n1 Newton is the force which when applied to a body of unit mass produces a unit acceleration in it. 1 newton would produce acceleration of 1 ms-2<\/sup> in a mass of 1 kg.<\/p>\n
\nThe acceleration produced bya force in an object is directly proportional to the applied FORCE and inversely proportional to the MASS of the object.<\/p>\n
\nSI unit of force is Newton (N).<\/p>\n
\nAcceleration is the physical quantity associated with N kg-1<\/sup>.<\/p>\n
\n1 N = 105<\/sup> Dyne.<\/p>\n
\nAs mass of loaded van is greater than sports car so it would require more force to stop.<\/p>\n
\nWe know force = mass x acceleration.
\na= f\/m = 12 N \/ 4 kg. = 3 ms-2<\/sup>
\nso acceleration of the body would be 3 ms-2<\/sup>.<\/p>\n
\nSI unit of force is Newton whereas CGS unit of force is dyne.
\n1 newton \/ 1dyne = 105<\/sup>.<\/p>\n
\nSI unit of momentum is kgms-1<\/sup>.<\/p>\n
\nMomentum is defined as the amount of motion contained in the body. It is given by the product of the mass of the body and its velocity.<\/p>\n
\nMomentum is the physical quantity associated with the motion of the body.<\/p>\n
\nMomentum is possessed by bodies in MOTION.<\/p>\n
\nA fast pitched soft ball has more momentum.<\/p>\n
\nSI unit of momentum is kgms-1<\/sup>\u00a0and CGS unit of momentum is g cms-1<\/sup>.
\nAnd their ratio is = 1000 x 100 gms-1<\/sup>= 1:10.<\/p>\n
\nA body at rest has zero momentum as its velocity is zero.<\/p>\n
\nAccording to Newton’s third law, for every action there is always an equal and opposite reaction.<\/p>\n
\nWhen a force acts on a body then this is called an action.<\/p>\n
\nNo, action and reaction never act on a same body they always act simultaneously on two different bodies.<\/p>\n
\n2nd law of motion gives the definition of force.<\/p>\n
\nNewton’s third law explains this statement.<\/p>\n
\nForce is a vector quantity.<\/p>\n
\nThis means these forces are balanced forces.<\/p>\n
\nPassengers tend to fall sideways when the bus takes a sharp turn due to the inertiaof direction.<\/p>\n
\nPassengers are thrown in the forward direction as the running bus stops suddenly because due to their inertia of motion, their upper body continues to be in the state of motion even though the lowerbody comes to rest when the bus stops.<\/p>\n
\nPassengers tends to fall in backward direction when bus starts suddenly because due to their inertia of rest, as soon as the bus starts, their lower body comes in motion but the upper body continues to be in the state of rest.<\/p>\n
\nNo, internal forces cannot change the velocity of a body.<\/p>\n
\nWhen a hanging carpet is beaten using a stick, the dust particles will start coming out of the carpet because the part of the carpet where the stick strikes, immediately comes in motion while the dust particle sticking to the carpet remains at rest . Hence a part of the carpet moves ahead alongwith the stick, and the dust particles fall down due to the earth’s pull.<\/p>\n
\nWhen we shake the branches of a tree, the fruits and leaves remain in state of rest while branches comes in rest so fruits and leaves are detached from the tree.<\/p>\n
\nWe know force = mass x acceleration
\nF1<\/sub> = 10 x 5 = 50 dyne.
\nF2<\/sub> = 20 x 2 = 40 dyne.
\nSo first body require more force.<\/p>\n
\n<\/p>\n
\nSolution 35:<\/strong><\/span>
\ninitial velocity of the object = 0 ms-1<\/sup>
\nAcceleration of the object = 8 ms-2<\/sup>.
\nTime = 5 s.
\nDistance covered would be S = ut + 1\/2 at2<\/sup>.
\nS = 1\/2 x 8 x 5 x 5 = 100 m.<\/p>\n
\nInitial velocity of the truck = 0 ms-1<\/sup>
\nDistance covered by truck = 100 m
\nTime taken to cover this distance = 10 s.
\nWe know Distance covered would be S = ut + 1\/2 at2<\/sup>.
\n100 =1\/2 x a x 100
\na= 2 ms-2<\/sup>.
\nMass of truck = 5 metric tons = 5000 kg.
\nForce acted on truck = mass x acceleration
\nForce = 5000 x 2 = 10000 N.<\/p>\n
\nMomentum is used for quantifying the motion of body.<\/p>\n
\nWhen we fire a gun, a force is exerted in the forward in the forward direction as the bullets comes out; in reaction to which an equal and opposite force is act in the backward direction and hence, we feel a backward jerk on the shoulder.<\/p>\n
\nA person applies force on water in backward direction and water according to third law of motion water apply an equal and opposite force in forward direction which helps a person to swim.<\/p>\n
\nNewton’s third law of motion is involved in the working of a jet plane.<\/p>\n
\nYes, a rocket can propel itself in a vacuum once it is given initial velocity.<\/p>\n
\nAction is equal and opposite to reaction but they act on different bodies and object moves as movement requires an unbalanced force and these are provided once inertia is overcome.<\/p>\n
\nSolution 1:<\/strong><\/span>
\nSir Isaac Newton stated the law of gravitation.<\/p>\n
\nEvery object in the universe attracts every other object with a force directly proportional to the product of their masses and inversely proportional to the square of distance between them.<\/p>\n
\nGravity is the force of attraction between the object and the earth whereas gravitation refers to the force of attraction that exists between any two bodies that possess mass.<\/p>\n
\nAcceleration due to gravity is the acceleration experienced by a body during free fall.<\/p>\n
\ng = GM\/R2<\/sup>.<\/p>\n
\nWe know that law of gravitation.
\nF = G ( m1<\/sub> x m2<\/sub>)\/R2<\/sup>.
\nHere G is universal constant and is called constant of gravitation. It doesnot depend upon on the value of m1<\/sub>, m2<\/sub> or R.
\nIts value is same between any two objects in the universe.<\/p>\n
\nSI unit of constant of gravitation is Nm2<\/sup>kg-2<\/sup>.<\/p>\n
\nwe know that law of gravitation.
\nF = G ( m1<\/sub> x m2<\/sub>)\/R2<\/sup>.<\/p>\n\n
\nF = 4 x G( m1<\/sub> x m2<\/sub>)\/ R2<\/sup>.
\nF1<\/sub>\u00a0= 4 F.<\/li>\n
\nF = G( m1<\/sub> x m2<\/sub>)\/ 4R2<\/sup>.
\nF1<\/sub> = F\/4.<\/li>\n
\nF = G( m1<\/sub> x m2<\/sub>)\/16 R2<\/sup>.
\nF1<\/sub> = F\/16.<\/li>\n
\nF = G( m1<\/sub> x m2<\/sub>)\/ R2<\/sup>.
\nF1<\/sub> = 0.<\/li>\n
\nF = G( m1<\/sub> x m2<\/sub>)\/ 0.
\nF1<\/sub>\u00a0= infinite.<\/li>\n<\/ul>\n
\nAll objects in the universe attract each other along the line joining their CENTRES.<\/p>\n
\nThe force of attraction between any two material objects is called FORCE OF GRAVITATION.<\/p>\n
\nThe gravitational force of the earth is called earth’s GRAVITY.<\/p>\n
\nThe Gravity is a particular case of GRAVITATIONAL FORCE OF EARTH.<\/p>\n
\nThe value of G is extremely SMALL.<\/p>\n
\nYes the law of gravitation is also applicable in case of the sun and moon.<\/p>\n
\nwe know that law of gravitation.
\nF = G ( m1<\/sub> x m2<\/sub>)\/R2<\/sup>.
\nMass of earth = 6 x 1024<\/sup>kg.
\nMass of the person = 100 kg.
\nG = 6.7 x 10-11 Nm2<\/sup>kg-2<\/sup>.
\nRadius of earth = 6.4 x 1014<\/sup>.
\nF = (6.7 x 10-11<\/sup>\u00a0x 100 x 6 x 1014<\/sup> )\/ (6.4 x 6.4 x 1012<\/sup>) = 981.4N
\nForce of gravity due to earth acting on a 100 kg person is 981.4 N.<\/p>\n
\nObjects fall towards the earth due to force of gravitation.<\/p>\n
\nBecause the masses of persons are not large enough to overcome the value of small constant of gravitation so the force of gravitation is very small and negligible to feel.<\/p>\n
\nInitial speed of ball is = 4.9 ms-1<\/sup>.
\nAcceleration due to gravity = -9.8 ms-2<\/sup>.<\/p>\n