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 =

1 st Law of Motion 1 st 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

1 st Law of Motion Law of Inertia. Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1 st 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

1 st Law of Motion Law of Inertia. Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1 st 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

1 st Law of Motion Law of Inertia. Inertia – Causes resistance to change in motion – Friction – A force that slows down motion. – 1 st 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 = t f - t i i = initial f = final Displacement = change in position = x x = x f - x i

Position-time graph Time interval t = t f - t i i = initial f = final Displacement = change in position = x x = x f - x i

Position-time graph Time interval t = t f - t i i = initial f = final Displacement = change in position = x x = x f - x i

Position-time graph Time interval t = t f - t i i = initial f = final Displacement = change in position = x x = x f - x i

Position-time graph Time interval t = t f - t i i = initial f = final Displacement = change in position = x x = x f - 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 = x f - x i t t f - t i = vertical coordinates horizontal coordinates X = instantaneous position Slope = x t Absolute value of velocity = speed 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 x i = 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 x i = initial position y = x (position) x = t (time) (0, 20) (4,0) y = mx + b m = 20-0 = m/s 0-4 y = (-5.0 m/s)x m x = vt + x i

Velocity x i = initial position y = x (position) x = t (time) (0, 20) (4,0) y = mx + b m = 20-0 = m/s 0-4 y = (-5.0 m/s)x m x = vt + x i x = (-5.0 m/s)t m

2 nd 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

2 nd 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

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 2 nd 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 2 nd Law of Motion Large force + small mass = high acceleration small force + large mass = low acceleration Larger force = higher acceleration

Falling objects – All objects fall at the same rate Large mass small mass 2 nd Law of Motion Big Force little acceleration Little force big acceleration

Falling objects – All objects fall at the same rate Large mass small mass 2 nd Law of Motion Big Force little acceleration Little force big acceleration

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 2 nd Law of Motion

3 rd 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)

3 rd 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)

3 rd 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

3 rd 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 M 1 V 1 = M 2 V 2 1 kg x 10 m/s = 5 kg x ___ m/s

3 rd 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

3 rd 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