Applications of Newton's Law

Newtons laws in practical life..& its explanation...

1. We Are… Group No: 12 SERIAL NO . Name Id no. 01 RASHEL AHMED 21-034 02 RUMANA BARKAT RUMU 21-191 03 MAIMUNA AKTER 21-121 04 Md. MAHABUB ALAM 21-260 05 PRANAB CHANDRA GHOSH 21-265

2. Our respected course teachers are: Course Name: General Science & Environment(F-110) Dept. of Finance , University of Dhaka Dr. Md. Zahangir Alam Professor(Dept. of Applied Chemistry & Chemical Engineering, DU) Dr. Ratan Chandra Gosh Associate Professor (Dept. of Physics, DU)

3. We are Assigned… Applications of Newton’s Laws in Real Life

4. Now You are with … RASHEL AHMED Id No: 21-034

5. Newton (1642-1726) Sir Issac Newton was an English Physicist and mathematician and a well known Scientist. He discovered 3 laws of motion & Universal Gravitational Law. We will discuss about them in the next slides.

6. Newton’s law of Motion Sir Isaac Newton discovered the 3 laws of motion. 1 st law(Inertia) 2 nd law 3 rd law

7. Newton’s Laws of Motion Newton’s First Law: Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless acted upon by an unbalanced force. Newton’s Second Law: Force equals mass times acceleration (F = ma). Newton’s Third Law: For every action there is an equal and opposite reaction.

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9. An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force. Newton’s First Law Newton’s First Law of Motion

10. Newton’s 1 st law An object at rest remains at rest and on object in motion remains in motion with the same speed and direction. Newton’s First Law of Motion

11. What does this mean? Basically, an object will “keep doing what it was doing” unless acted on by an unbalanced force. If the object was sitting still, it will remain stationary. If it was moving at a constant velocity, it will keep moving. It takes force to change the motion of an object.

12. Law of Inertia Newton’s first law is also called law of inertia. Inertia: It is the inability of the body to change the state of motion and its state of rest by itself. Which is directly related to the first law of Motion.

13. Newton’s First Law

14. Real life examples of Newton's first law 1.When a bus suddenly starts, the passengers sitting or standing in the bus tend to fall backward. This is due to inertia of rest and can be explained as follows: when the bus suddenly starts, the lower part of the body of the passenger which is in contact with the bus moves along with the bus while the upper part of the body tends to retain its state of rest due to inertia. As a result, the passenger falls backward.

15. Real life examples of Newton's first law

16. Real life examples of Newton's first law 2. When a branch of a tree is vigorously shaken the fruits and seeds in It fall down to inertia of rest.

17. Real life examples of Newton's first law 3.  A rider on a running horse is thrown forward when the horse stops suddenly due to inertia of motion.

18. Now You are with … Md. MAHABUB ALAM Id No: 21-260

19. Force equals mass times acceleration. F = ma Newton’s Second Law Acceleration : a measurement of how quickly an object is changing speed. Newton’s Second Law

20. Newton’s Second Law Force is directly proportional to mass and acceleration. Which is F=ma. * Imagine a ball of a certain mass moving at a certain acceleration. This ball has a certain force. * Now imagine we make the ball twice as big (double the mass) but keep the acceleration constant. F = ma says that this new ball has twice the force of the old ball.

21. Newton’s Second Law * Now imagine the original ball moving at twice the original acceleration. F = ma says that the ball will again have twice the force of the ball at the original acceleration.

22. What does F = ma say? F = ma basically means that the force of an object comes from its mass and its acceleration. If you double the mass, you double the force. If you double the acceleration, you double the force. Doubling the mass and the acceleration quadruples the force. (2m)(2a) = 4F So . . . what if you decrease the mass by half ? How much force would the object have now?

23. Real life examples of Newton's 2 nd law THIS LAW STATES… Newton's second law states that the speed of acceleration of a moving object depends on the object's mass and the force being exerted on it.

24. Real life examples of Newton's 2 nd law 1. One instance of this is the understanding that it requires much more force to push a vehicle than to kick a soccer ball.

25. Real life examples of Newton's 2 nd law 2 . Simply, Newton's second law represents the fact that the greater the mass of an object, the more force there is needed in order to move it. This explains why, for example, it requires one person to easily lift a box weighing five pounds but multiple people exerting more force collectively to lift a box weighing 100 pounds.

26. Real life examples of Newton's 2 nd law

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28. Newton’s Third Law of Motion For every action there is an equal and opposite reaction.

29. Law of Interaction “In every action , there is always an equal and opposite reaction ”

30. Newton’s Laws of Motion 3 rd Law States – When one object exerts a force on another object, the 2nd object exerts an equal and opposite force back on the 1st object.

31. APPLICATION OF THIRD LAW OF MOTION While firing a bullet , the gun must be held tight to the shoulder. When a man jumps from a boat to the shore, the boat slightly moves away from the shore. When a bullet is fired from a gun, the gun recalls or gives a kick in backward direction. Rocket works on the principle of conservation of momentum. If some one left on a frictionless floor desire to get out of it, he can do so by blowing air out of his mouth.

32. Newton’s 3rd Law in Nature Consider the propulsion of a fish through the water. A fish uses its fins to push water backwards. In turn, the water reacts by pushing the fish forwards, propelling the fish through the water. The size of the force on the water equals the size of the force on the fish; the direction of the force on the water (backwards) is opposite the direction of the force on the fish (forwards).

33. Newton’s 3rd Law in Nature Flying gracefully through the air, birds depend on Newton’s third law of motion. As the birds push down on the air with their wings, the air pushes their wings up and gives them lift.

34. Other examples of Newton’s Third Law The baseball forces the bat to the left (an action); the bat forces the ball to the right (the reaction).

35. Application of Newton’s 3 rd Law Action: man jumps from boat to the shore Reaction: boat slightly moves away from the shore(recoils)

36. Application of Newton’s 3 rd Law The reaction of a rocket is an application of the third law of motion. Various fuels are burned in the engine, producing hot gases. The hot gases push against the inside tube of the rocket and escape out the bottom of the tube. As the gases move downward, the rocket moves in the opposite direction.

37. Now You are with … PRANAB CHANDRA GHOSH ID No: 21-265

38. Newton’s Laws(Cont’d) Newton’s Law Of Gravitation

39. The idea of gravity was Introduced by Sir Isaac Newton in the late 1600’s He was a scientist who combine ideas to explain how the universe operates

40. All Matter Is Affected by Gravity Because of gravity you are being pulled toward your book, your pencil, and every other object around you. You exert an attractive force on everything around you and everything is exerting an attractive force on you. This attractive force is called gravity. All objects experience an attraction toward all other objects in this universe.

41. Newton’s Universal Law of Gravitation (Cont’d ) This Law States….. Every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of the masses of the particles and inversely proportional to the square of the distance between them .

42. Gravitational Force Gravitation force depends on two things: The mass of the two objects The distance between the two objects G  The Universal Gravitational Constant It is the same everywhere in the Universe G = 6.673  10 -11 N ∙ m 2 /kg 2 Always same on every location

43. Gravitational force is directly proportional to the product of masses. Newton’s Universal Law of Gravitation (Cont’d )

44. Gravitational Force and Distance Gravity between any person and the earth is greater than the gravity between the person and the sun. Gravitational force decreases as distance increases. Newton’s Universal Law of Gravitation (Cont’d)

45. Gravitational force is inversely proportional to the square of distance between the masses

46. Gravitational Force and Mass Earth attracts an elephant more than a cat. Earth attracts coconut more than an apple. Earth’s gravitational force is greater than that of moon. Gravitational force increases as mass increases.

47. Mass, Distance AND Gravitational Force

48. Examples of Gravitation...... Some examples are—

49. Examples of Gravitation...... Brick’s recurring pushing on ground

50. Any Query?