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Notes – Representing Motion Laws of Motion • Isaac Newton – 1686 – English scientist discovered the three laws of motion • Motion – The change in position when compared to a reference point – Reference point – A place or object used to determine if something is in motion Laws of Motion • Isaac Newton – 1686 – English scientist discovered the three laws of motion • Motion – The change in position when compared to a reference point – Reference point – A place or object used to determine if something is in motion Laws of Motion • Isaac Newton – 1686 – English scientist discovered the three laws of motion • Motion – The change in position when compared to a reference point – Reference point – A place or object used to determine if something is in motion Laws of Motion • Isaac Newton – 1686 – English scientist discovered the three laws of motion • Motion – The change in position when compared to a reference point – Reference point – A place or object used to determine if something is in motion • Are we in motion? • 1 day = • Earth circumference = • Distance / Time = • Earth’s orbit around sun= • Time for orbit = • Distance/Time = Laws of Motion • Isaac Newton – 1686 – English scientist discovered the three laws of motion • Motion – The change in position when compared to a reference point – Reference point – A place or object used to determine if something is in motion • Are we in motion? • 1 day = • Earth circumference = • Distance / Time = • Earth’s orbit around sun= • Time for orbit = • Distance/Time = 1st Law of Motion • 1st Law : Bodies at rest stay at rest, bodies in motion stay in motion unless acted upon by another force. Law of Inertia. • Inertia – Causes resistance to change in motion 1st Law of Motion • Law of Inertia. • Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1st Law examples: It takes force to move an object. A hockey puck slides in a straight line across ice. Gravity keeps things stationary on earth 1st Law of Motion • Law of Inertia. • Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1st Law examples: It takes force to move an object. A hockey puck slides in a straight line across ice. Gravity keeps things stationary on earth 1st Law of Motion • Law of Inertia. • Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1st Law examples: It takes force to move an object. A hockey puck slides in a straight line across ice. Gravity keeps things stationary on earth Motion • Motion diagram – Shows the position of a moving object at equal time intervals • Particle model – replaces objects with single points located at a central point on the object Motion • Motion diagram – Shows the position of a moving object at equal time intervals • Particle model – replaces objects with single points located at a central point on the object Motion • Motion diagram – Shows the position of a moving object at equal time intervals • Particle model – replaces objects with single points located at a central point on the object Motion • Coordinate system Origin = all points zero (0) = position [------ distance -------] Magnitude = quantities of size Vector = Magnitude and direction direction [------magnitude ----] Scalar = no direction ( 5m) Motion • Coordinate system Origin = all points zero (0) = position [------ distance -------] Magnitude = quantities of size Vector = Magnitude and direction direction [------magnitude ----] Scalar = no direction ( 5m) Position-time graph • Time interval t = tf - ti i = initial f = final Displacement = change in position = x x = xf - x i Position-time graph • Time interval t = tf - ti i = initial f = final Displacement = change in position = x x = xf - x i Position-time graph • Time interval t = tf - ti i = initial f = final Displacement = change in position = x x = xf - x i Position-time graph • Time interval t = tf - ti i = initial f = final Displacement = change in position = x x = xf - x i Position-time graph • Time interval t = tf - ti i = initial f = final Displacement = change in position = x x = xf - x i Speed and Velocity Speed is equal to distance over time. • S=D/t • If you travel 10 meters in 5 seconds, your speed is 10 m / 5 s = • 2 m/s meters/second Velocity is equal to speed and direction • 2 m/s east Vector – shows magnitude and direction Velocity • Average velocity = v= x = xf - xi t tf - ti = vertical coordinates horizontal coordinates X = instantaneous position x t Absolute value of velocity = speed Slope = Avg. speed + direction = velocity V = instantaneous velocity Velocity • Straight line equation • y = mx + b • y = quantity plotted on vertical axis • x = quantity plotted on horizontal axis • m = line’s slope • b = lines y-intercept xi = initial position y = x (position) x = t (time) Velocity • • • • • • Straight line equation y = mx + b y = quantity plotted on vertical axis x = quantity plotted on horizontal axis m = line’s slope b = lines y-intercept xi = initial position y = x (position) x = t (time) (0, 20) (4,0) y = mx + b m= 20-0 = - 5.0 m/s 0-4 y = (-5.0 m/s)x + 20.0 m x = vt + xi Velocity • xi = initial position y = x (position) x = t (time) (0, 20) (4,0) y = mx + b m= 20-0 = - 5.0 m/s 0-4 y = (-5.0 m/s)x + 20.0 m x = vt + xi x = (-5.0 m/s)t + 20.0 m 2nd Law of Motion • Acceleration of an object depends on the amount of mass and the size of the force. • Acceleration = change in speed or velocity over time. It could be speeding up, slowing down, or changing directions 2nd Law of Motion • Acceleration of an object depends on the amount of mass and the size of the force. • Acceleration – change in speed or velocity over time. It could be speeding up, slowing down, or changing directions 2nd Law of Motion • The acceleration of an object is directly proportional to the force and inversely proportional to the mass • a = F / m acceleration = Force / mass Large force = large acceleration Large mass = small acceleration 2nd Law of Motion • The acceleration of an object is directly proportional to the force and inversely proportional to the mass • a = F / m Large force + small mass = high acceleration small force + large mass = low acceleration acceleration = Force / mass Large force = large acceleration Large mass = small acceleration Larger force = higher acceleration 2nd Law of Motion • Falling objects – All objects fall at the same rate • Large mass small mass Little force big acceleration Big Force little acceleration 2nd Law of Motion • Falling objects – All objects fall at the same rate • Large mass small mass Little force big acceleration Big Force little acceleration 2nd Law of Motion • Air resistance– Air friction slows down falling objects • In a vacuum (no air) a feather would fall at the same rate as a bowling ball 3rd Law of Motion • If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction. • For every action (force) there is an equal and opposite reaction (force) 3rd Law of Motion • If one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction. • For every action (force) there is an equal and opposite reaction (force) 3rd Law of Motion • For every action (force) there is an equal and opposite reaction (force) • Ex: Recoiling of a fired gun, a balloon travels in the opposite direction of air flow 3rd Law of Motion • Momentum - An object’s mass multiplied by its velocity • Conservation of Momentum – When two or more objects collide, the total momentum of the object is the same after as before • M1V1 = M2V2 1 kg x 10 m/s = 5 kg x ___ m/s 3rd Law of Motion • Conservation of Momentum – When two or more objects collide, the total momentum of the object is the same after as before • Angular momentum – Velocity of rotation increases as the distance from the center becomes smaller 3rd Law of Motion • Conservation of Momentum – When two or more objects collide, the total momentum of the object is the same after as before • Angular momentum – Velocity of rotation increases as the distance from the center becomes smaller Force • Force - Any push or pull acting on an object • Measured in Newtons (N) Fundamental Forces • 1) Gravity – Causes an attraction between the mass of objects and produces weight • 2) Electromagnetic Causes an attraction between positive and negative charges • 3) Nuclear – Strongest fundamental force. It holds protons and neutrons together in the nucleus of atoms Fundamental Forces • 1) Gravity – Causes an attraction between the mass of objects and produces weight • 2) Electromagnetic Causes an attraction between positive and negative charges • 3) Nuclear – Strongest fundamental force. It holds protons and neutrons together in the nucleus of atoms Fundamental Forces • 1) Gravity – Causes an attraction between the mass of objects and produces weight • 2) Electromagnetic Causes an attraction between positive and negative charges • 3) Nuclear – Strongest fundamental force. It holds protons and neutrons together in the nucleus of atoms Energy • Energy is the ability to do work • Energy enables forces to move objects 2 main types • Potential • Kinetic 1) Potential Energy • Potential energy is stored in an object as a result of its position • Examples: Book on a shelf, rock on a cliff, stretched rubber band 2) Kinetic Energy • Kinetic energy is the energy of motion and moving objects. It is the energy in falling or moving objects • Ex: Pendulum – Bob on a string. Changes from potential to kinetic to potential 2) Kinetic Energy • Kinetic energy is the energy of motion and moving objects. It is the energy in falling or moving objects • Ex: Pendulum – Bob on a string. Changes from potential to kinetic to potential Forms of Energy • 1) Mechanical – energy of motion or position (machines) • 2) Chemical – Changes one kind of matter to another. Battery electricity Food motion and heat Forms of Energy • 1) Mechanical – energy of motion or position (machines) • 2) Chemical – Changes one kind of matter to another. Battery electricity Food motion and heat Forms of Energy • 3) Heat – Moving molecules and changes in temperature • 4) Electric – Flow of electrons • 5) Electromagnetic – Rays which spread out and pass through space Ex: radio, light, UV, infrared Forms of Energy • 3) Heat – Moving molecules and changes in temperature • 4) Electric – Flow of electrons • 5) Electromagnetic – Rays which spread out and pass through space Ex: radio, light, UV, infrared Forms of Energy • 3) Heat – Moving molecules and changes in temperature • 4) Electric – Flow of electrons • 5) Electromagnetic – Rays which spread out and pass through space Ex: radio, light, UV, infrared Forms of Energy • 6) Nuclear – Changes in nuclei of atoms. Most concentrated form . Ex: Atomic power plants