3.2 Newton’s First Law of Motion Every year in Canada there are approximately 160 000 car accidents, 3000 of which are fatal. Many of these injuries and.

Slides:



Advertisements
Similar presentations
DYNAMICS The study of why objects move or dont move.
Advertisements

Newton’s Laws of Motion
4.05 Determine factors that affect motion including:
Newton’s FIRST Law Of Motion.
Your science book sits on the table until you pick it up. If you hold your book above the ground, then let go, gravity pulls it to the floor. An object.
6.1 Newton’s First Law pp
The Laws of Motion Chapter The First Two Laws of Motion Section 4-1 The British Scientist Isaac Newton published a set of three rules in.
What is force? A force is a push or pull. Sometimes it is obvious that a force has been applied. 2.3 Motion and Forces But other forces aren't as noticeable.
Newton’s Laws 1. F. Newton’s Laws of Motion  Kinematics is the study of how objects move, but not why they move.  Sir Isaac Newton turned his attention.
Newton’s Laws of Motion. Sir Isaac Newton ( )  an English scientist and mathematician famous for his discovery of the law of gravity also discovered.
Forces Newton’s Laws of Motion “If I have seen far, it is because I have stood on the shoulders of giants.” - Sir Isaac Newton (referring to Galileo)
Newton’s 1st and 2nd law Inertia and pressure In terms of collisions
Newton’s first law of motion
Newton’s Laws of Motion
Forces and Motion. Aristotle: Natural Motion: light objects rise, heavy objects fall Violent Motion: motion contrary to an object’s nature, requires an.
Section 1Forces Bellringer The concept of force explains many occurrences in our everyday lives. From your own experience, state what will happen in the.
Chapter 4 - Laws of Motion
Newton’s Laws of Motion Forces cause changes in motion.
Chapter Six: Laws of Motion
Newton’s Laws of Motion
Newton’s First Law of Motion. First we need to define the word FORCE: The cause of motion (what causes objects to move) Two types of forces –Pushes –Pulls.
Newton’s First Law of Motion. Introduction It is an everyday experience that if you push or pull a stationary object it will start to move. It is also.
Newton’s 1 st Law of Motion by: Heather Britton. Newton’s 1 st Law of Motion We have learned what happens to an object once it is set in motion Now we.
Chapter Six: Laws of Motion
Newton's Laws This is where the real physics begins. Physics is more than equations and math problems -- it is the laws of the universe and, most importantly,
Newton’s 1 st Law Inertia. Force Anything capable of changing an object’s state of motion Any push or pull Causes object to speed up, slow down, or change.
Section 2 Newton’s First and Second Laws of Motion.
 An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted.
Newton's First Law of Motion. Newton's first law of motion states that an object at rest will remain at rest, and an object moving at a constant velocity.
Motion & Forces Defining Force Defining Force  Force  Newton’s First Law  Friction.
11.1 Newton’s First Law. INERTIA An object at rest remains at rest, and an object in motion maintains its velocity unless it experiences an unbalanced.
Motion & Forces Defining Force Defining Force  Force  Newton’s First Law  Friction.
Force and Motion ISCI Force: ‘push’ or ‘pull’ on an object 2. Objects in motion stay in motion unless enacted upon by a ‘unbalanced’ force. Newton’s.
Newton’s First Law. INERTIA An object at rest remains at rest, and an object in motion continues with constant velocity unless it experiences a net external.
Chapter 4 Newton’s First Law of Motion The Law of Inertia.
Newton’s First Law. Galileo’s View of Force & Motion  Prior to the 1600s, early scientists held simplistic views of motion  They noticed that moving.
November 4, 2015 I will be expected to know how Newton’s First Law of Motion affects the world around me.
Who was Sir Isaac Newton? Born in England, Isaac Newton was a highly influential physicist, astronomer, mathematician, philosopher, alchemist and theologian.
NEWTON’S 3 LAWS OF MOTION 12.2 & SCIENTISTS HAVE CONTRIBUTED TO OUR UNDERSTANDING OF FORCE & MOTION ARISTOTLE: AN ANCIENT GREEK SCIENTIST AND.
Laws of Motion Newton’s First Law. Force changes motion A force is a push or pull, or any action that is able to change motion.
Unit 4 Lesson 3 Newton’s Laws of Motion
2-1 Notes – Combining Forces
Newton’s First Law of Motion
Newton’s First Law What makes an object speed up, slow down, or change directions? Objects change their state of motion only when a net force is applied.
Newton’s Laws of Motion
The Laws of Motion The First Law of Motion
Newton’s Laws of Motion
2.2: Inertia & Newton’s First Law
Unit 4 Lesson 3 Newton’s Laws of Motion
S I R I S A A C N E WTON ( ) JP ©.
Newton’s FIRST Law Of Motion.
NEWTON’S LAWS OF MOTION
Newton’s First Law of Motion
MOTION & ITS APPLICATIONS  Newton’s First Law of Motion (P )
Newton’s 1st Law The Law of Inertia.
Newton’s Laws of Motion
6.1 Newton’s First Law pp
Chapter 13 Section 3 Newton’s Laws of Motion
Laws of Motion and Energy
Newton’s Laws of Motion
Chapter 6 Newton’s First Law.
Forces and Motion.
Chapter 12 Mr Hodesblatt.
Forces all around us.
Newton’s First Law.
Newton's Laws of Motion.
Newton's Laws of Motion.
Newton 1st Law of Motion.
Chapter 13 Section 3 Newton’s Laws of Motion
Chapter 6 - Forces In Motion
Presentation transcript:

3.2 Newton’s First Law of Motion Every year in Canada there are approximately car accidents, 3000 of which are fatal. Many of these injuries and deaths involve motorists who are not wearing seat belts or are driving too fast. What happens to motorists who are not wearing seat belts during a collision? Newton’s First Law will help answer this question.

3.2 Newton’s First Law of Motion Early scientists and philosophers thought that a constant net force was required to keep an object moving. Larger net forces caused objects to move at higher constant speeds. No net force meant the object would stop. In the 1600s, Galileo demonstrated, through a simple thought experiment involving a ball and some ramps, that if there was no friction present, the ball will continue to roll until it reached the same height as its starting position on the first ramp. If the second ramp is eliminated, the ball would continue to roll forever because it will never reach the same initial height of the first ramp. Remember, no friction is present.

3.2 Inertia Galileo concluded that once an object starts moving, it will continue to move at a constant velocity if no friction is present. He used the concept of inertia to explain his conclusion; Inertia is the property of matter that causes an object to resist changes in motion. Inertia is directly proportional to the mass of the object. (Inertia α mass) As the mass of an object increases, its inertia increases; As the mass decreases, its inertia decreases.

3.2 Newton’s First Law Sir Isaac Newton published Principia Mathematica, a set of books which included much of his work on physics, as well as a description of Galileo’s law of inertia. The law of inertia is also known as Newton’s First Law of Motion because it was included with Newton’s other laws of motion. Newton’s First Law of Motion states that if the net force acting on an object is zero, the object will remain at rest or continue to move with a constant velocity.

3.2 Newton’s First Law There are many implications of Newton’s First Law: If the velocity of an object is constant, then the net force acting on it is zero; same as if the object were at rest. Objects at rest tend to remain at rest; objects in motion tend to remain in motion in a straight line with a constant speed until acted on by an unbalanced force. If a net force acts on an object, the velocity of the object will change in magnitude or direction; the object will undergo acceleration. SP #1,3 p

3.2 Applications of Newton’s First Law How do headrests prevent injuries? During a rear-end collision, the car will suddenly accelerate forward and so will your body because the seat exerts a force on your torso. In a vintage car with no headrest, no force is applied to your head. According to Newton’s First Law, it remains at rest. Your head will initially appear to snap backwards, relative to your body accelerating forward, resulting in whiplash.

3.2 Applications of Newton’s First Law How do headrests prevent injuries? The head rest in a modern car helps push the head forward with the rest of the body. This helps to prevent whiplash since your neck does not bend as far back during a rear-end collision.

3.2 Applications of Newton’s First Law How do seat belts work? One design feature of a seat belt uses the sudden decrease in velocity to activate a gear mechanism. The seat belt strap is attached to a spool, which in turn is attached to a gear. Beneath the gear is a pendulum that is free to swing back and forth. When the vehicle is moving at a constant velocity, the pendulum freely hangs straight down.

3.2 Applications of Newton’s First Law How do seat belts work? When the car comes to a sudden stop, the pendulum swings forward due to its inertia. This causes the pendulum to move a metal stop into the teeth of the gear mechanism, locking the seat belt in place.

3.2 Homework Practice # 1, 4, 5 p.126 Questions # 3, 4, 6, 8, 9, 13 p.122