Chapter 3 Motion in a line (linear motion). Motion Vocabulary A cat moves a distance of 10 meters (how far?) in 5 seconds. What information do you KNOW.

Slides:



Advertisements
Similar presentations
L-3 Gravity and Free Fall
Advertisements

L-4 constant acceleration and free fall (M-3)
Objects in Free Fall 2.7. What is gravity?  Gravitation is a natural phenomenon by which objects with mass attract one another.natural phenomenonmass.
Today’s Topic Free Fall What is Free Fall? Free Fall is when an object moves downward (vertically) only as the result of gravity.
Free falling …. ACCELERATION DUE TO GRAVITY All bodies in free fall (that is no air resistance) near the Earth's surface have the same downward acceleration.
Air resistance is a form of friction that acts to slow down any object moving in the air. Air resistance is a force that gets larger as an object moves.
One-Dimensional Motion. Experience vs. Experiment Through evolution and memory, humans have developed a “sense” for motion  Developed over years of observation,
Chapter 2 Motion in One Dimension (Kinematics). 2.1 Displacement and Velocity Distance is a measure of the total motion of an object (how far it has traveled)
Making Sense of the Universe (Chapter 4) Why does the Earth go around the Sun? Part, but not all, of Chapter 4.
Speed, Velocity and Acceleration
Studying the Force of Gravity
Newton’s Second Law Chapter 4 Net Force causing acceleration Friction Air resistance.
Motion is one of the key topics in physics. Everything in the universe moves. It might only be a small amount of movement and very very slow, but movement.
Do Now Monday, 4/2 Take our your notebook and answer the following question: What is the difference between weight and mass? You have 4 minutes. I will.
Motion and Force Chapter Twelve: Distance, Time, and Speed Chapter Thirteen: Forces Chapter Fourteen: Force and Motion.
Change in Motion Motion When something moves, its in motion. Motion is change in an object’s position. A motionless object is at rest or stationary.
Part 4 Newton’s Second Law of Motion Newton’s Second Law Acceleration is the rate at which your velocity (speed with direction) changes.
SACE Stage 1 Conceptual Physics 2. Motion. 2.1 Motion is Relative Everything moves. Things that appear to be at rest move. Everything moves. Things that.
The Ordered Universe Part 3: Some Calculations. Check Prior Knowledge: Summarize the contributions made by Galileo and Newton Distinguish between speed,
G RAVITY February 9, J OURNAL : 2/9/2011 A soccer ball is pushed with a force of 15.2 N. The soccer ball has a mass of 2.45 kg. What is the ball’s.
Chapter 6 Forces and motion.
 Define the term motion.  Give an example of something in motion.  How do we know an object is in motion?  How do we know if we are in motion even.
DISPLACEMENT AND VELOCITY Chapter 2-1. Objectives Describe motion in terms of frame of reference, displacement, time and velocity. Calculate displacement,
A Solidify Understanding Task
ACCELERATION What is Acceleration  The increase in the rate or speed of something.
Questions: Do heavier objects fall faster than lighter ones when starting from the same position? Does air resistance matter? If the free fall motion has.
Units to read: 14, 15, 16, 17,18. Mass and Inertia Mass is described by the amount of matter an object contains. This is different from weight – weight.
Unit 4 – Lecture 2. Acceleration Acceleration – the rate of change of velocity change in velocity over a change in time a acceleration t f - t i change.
Accelerated Motion Acceleration Acceleration: the rate at which velocity changes Acceleration = Unit:
PHY115 – Sault College – Bazlurslide 1 Linear Motion.
Unit F Chapter 2 Ch 2 Lesson 1 Investigation Have you ever been on a moving bus, car or train? What happens if you your standing and the vehicle starts,
Chapter: Force and Newton’s Laws
TOPIC I.. I. Branch of Mechanics that deals with motion without regard to forces producing it. Branch of Mechanics that deals with motion without regard.
Chapter 6 Forces in Motion.
< BackNext >PreviewMain Chapter 13 Forces and Motion Preview Section 1 Gravity: A Force of AttractionGravity: A Force of Attraction Section 2 Gravity and.
LINEAR MOTION UNIT ONE PHYSICS ONE. I CAN:  DEFINE MOTION  DEFINE SPEED  DEFINE VELOCITY  EXPLAIN HOW VELOCITY CHANGES  CALCULATE AVERAGE VELOCITY.
Physics 101 Please pick up a clicker! Reminder: All lecture notes posted, after lecture, follow link at:
Physics the study of the relationship between matter and energy
Newton’s Second Law Chapter 4 Net Force causing acceleration Friction Air resistance.
Learning Target 5 → Free Fall: I can use the acceleration of gravity to describe and calculate an object's motion 5.1 I can describe how and why the rate.
Chapter 3 Motion in a line (linear motion). Motion Vocabulary A cat moves a distance of 10 meters (how far?) in 5 seconds. What information do you KNOW.
Unit 11, problem 3, 16 Unit 12, problem 5, 8, 10, 11, 12 Unit 14, problem 13, 14 Unit 15 problem 10, 13.
Free Fall Do heavier things fall faster than lighter things?
Kinematics Kinematics is the branch of physics that describes the motion of points, bodies (objects) and systems of bodies (groups of objects) without.
Units are covered. Galileo Galilei ( ) Using a Dutch-designed telescope that he built himself, he made several startling observations that.
Gravity Newton realized that a force acts to pull objects straight down toward the center of Earth. He called this force gravity. Gravity is the force.
Target Thursday January 3, What is gravity? 2.How do you know it is there? 3.What causes gravity? 4.Name 3 things that are in motion in this room.
 Vertical projectile motion deals with objects that fall straight down, objects that get thrown straight up and the motion of an object as it goes straight.
VERTICAL ONE DIMENSIONAL MOTION.  Relate the motion of a freely falling body to motion with constant acceleration.  Calculate displacement, velocity,
Free Fall A woman hits her car brakes in a panic stop and decelerates at a rate of 5 m/s 2. The car comes to rest at a distance of 62.5 m from the point.
Forces and Motion Falling Water Activity 1. What differences did you observe in the behavior of the water during the two trials? 2. In trial 2, how fast.
Forces and Motion CHAPTER 6. Gravity and Motion Aristotle (round 400 BC) believed that heavier objects fell to the earth faster than lighter objects.
Chapter 4 Linear Motion. Position, Distance, and Displacement Position: being able to describe an object’s location is important when things start to.
Science Vocabulary – meanings are different than everyday life Velocity – speed AND direction Acceleration – any change in velocity –Changing speed (getting.
Lecture 2 Objects in Motion Aristotle and Motion Galileo’s Concept of Inertia Mass – a Measure of Inertia Net Force and Equilibrium Speed and Velocity.
Chapter 4 Newton’s laws & gravity NOTE TO THE STUDENT: The teacher version of these slides has MANY more clicker questions than your notes. That is done.
Gravity and Motion What You’ll Do
Section 12-2 Newton’s Laws.
GRAVITY.
Chapter 11 Section 2.
Unit 7 Lesson 2. Gravity: A Force of Attraction A
Gravity.
3 Linear Motion Speed Velocity Acceleration Free Fall Dr. Jie Zou
Chapter 13 Preview Section 1 Gravity: A Force of Attraction
Motion in a Straight Line
S-9 Define the term motion. Give an example of something in motion.
S-9 Define the term motion. Give an example of something in motion.
How does gravity affect falling objects?
Chapter 4 Linear Motion.
Newton’s First Law & Linear Motion
Presentation transcript:

Chapter 3 Motion in a line (linear motion)

Motion Vocabulary A cat moves a distance of 10 meters (how far?) in 5 seconds. What information do you KNOW from this? What can you calculate? Speed (technically average speed) = dist/time –Most common units: meters/sec (or miles/hour) Velocity – speed AND direction –This is the quantity scientists use. Velocity tells us how fast things are moving with extra detail direction.

Speed/velocity questions Questions: a car moves 20 meters/sec. How far does it go in: –3 seconds? _______________ –10 seconds? _______________ –1 minute? _______________ –1 hour? _______________ Describe how something could move with constant speed but CHANGING velocity.

When you’re sitting completely still, are you moving? 1.Yes 2.No

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

Motions Daily motion – Earth’s rotation once per __ –Speed varies: ___ for Santa, 1000 mph for Ecuador 850 mph for Los Angeles Yearly motion – Earth’s revolution once per __ –Distance: 1AU = ____ –Speed: average ~66,000 mph –Direction “tilted” 23.5˚ relative to rotation. Sun orbits Milky Way center once per Million yr –28,000 light-year radius, speed ~500,000 mph –Studying this motion  dark matter discovered Galaxies moving relative to each other. –Nearest galaxies get closer to us. Most move away.

Acceleration Acceleration – any change in velocity –Changing speed (getting faster OR slower) –AND/OR Changing direction In everyday English, slowing down is called “decelerating” but physicists use “accelerating” to mean ANY form of acceleration/deceleration. Give some examples of things that are “accelerating” in the physics sense.

Velocity vs. acceleration Identify the following as velocity (arm points right) or acceleration (arm points left) –Going 55 mph –Using the gas pedal on your car –Rolling in a straight line –Using the brakes on your car –Using the steering wheel on your car –Running 10 meters per second –Things falling due to gravity. –Things thrown upwards on their way up to the top

Which does the human body feel? Velocity 2.Acceleration

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand. ** For this question, the same is true for ALL objects. They FEEL acceleration.

Accelerating – changing velocity When things accelerate, they change velocity in a predictable way –Cars go from zero to ____ in ____ seconds. –That’s an acceleration of _______________ –Sprinters run at a top speed of _________ meters/sec (or _____mph). –How long does it take to speed up? (Or slow down?) –Calculate the accelerations.

Airplanes travel at a constant speed of 400 miles/hr. Is the airplane accelerating? Yes 2.No 3.Not enough information provided

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

Two track demo See page 57, question 40. Clicker question coming: –Which reaches end of track first?

Which ball reaches the end of the track first? Same time 2.Ball on a straight path 3.Ball on the downhill/uphill path

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

Acceleration changing an object’s speed Ramp demo Imagine something accelerates at a constant rate of 2 miles/hr per second of motion. It starts at rest. Work with your neighbor. –Initially, its speed is _____________ –After 1 second, its speed is ____________ –After 2 second, its speed is ____________ –After 3 second, its speed is ____________ –After 10 secs, its speed is ____________ –After 2000 secs, its speed is ____________ –Write a rule for the speed after “T” seconds. –After you write your rule, notice the textbook gives an equation on page 47.

A super-fast car and truck start at the same place. The car goes 100 m/s (220 miles/hr) always. The truck starts at rest and accelerates 1 m/s per HOUR. Will the truck ever catch the car? Yes 2.No 3.Not enough information is provided

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

When the truck catches the car, which vehicle covered more distance? Car 2.Truck 3.Same 4.Not enough information is provided

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

When the truck catches the car, which vehicle is moving faster? Car 2.Truck 3.Same 4.Not enough information is provided

Debrief Talk to your neighbors: –Did you get it right? –Why or why not? –Make sure you understand.

Extra credit question – due Monday For 3 points, determine how much time it takes the car to catch the truck. Do NOT use any equations other than this one: –Velocity = acceleration * time –(You may not even need this equation) Your answer must be conceptual (i.e. words) not mathematical. Reminder: The car goes 100 m/s always. The truck starts at rest and accelerates 1 m/s per HOUR. Due Monday

Calif. Science Standards for motion From California Science Standards, grade 2: –Students know the way to change how something is moving is by giving it a push or a pull. The size of the change is related to the strength, or the amount of force, of the push or pull. And from grade 8: –Students know the velocity of an object must be described by specifying both the direction and the speed of the object. –Students know changes in velocity may be due to changes in speed, direction, or both.

Gravity near ground Free fall –Toss something up, what happens on way up? –Drop something, what happens on way down? When things fall, measure same accel. for: –speeding up –slowing down. –10 meters/sec (=22 mph) per second of falling. Paper/pen experiment SAME GRAVITATIONAL ACCELERATION for ALL objects, all masses, everywhere near ground.* –*Unless there are other forces, such as _____________ –Then we’re dealing with NET force, not gravity’s force. Galileo observed this (in Pisa). Galileo’s observations helped Newton formulate ideas.

From Apollo 15 mission Men on the Moon Show the hammer-feather movie (Vakil’s computer  Videos  Planets & Moons  hammer)

Gravitational acceleration g = 10 m/s per second or 22 mph per sec Drop something from rest. How fast will it be moving after: –1 sec _______________ –2 sec _______________ –10 sec _______________ –T sec _______________* *After writing your rule, compare yours to the book’s version on p. 48 –10 m/s 2 (on Earth’s surface) is abbreviated “g”** **More precisely it’s 9.8 m/s 2.

Free fall questions What happens to an object if you drop it at rest? –How quickly? If you toss something straight upwards –What happens on the upwards part of motion? How quickly? –What happens on the downward part? How quickly?

How fast is something moving at the top of the motion after being thrown upwards? The answer depends on: Nothing – it is moving w/ speed=zero 2.how fast it was thrown 3.How long you wait 4.how fast thrown & how long you wait

What is the acceleration at the top of the motion after being thrown upwards? Zero 2.g 3.Not enough information provided

You have two spheres of equal size and smoothness, and you can ignore air resistance. One is heavy, the other much lighter. You hold one in each hand at the same height above the ground. You release them at the same time. What will happen? 1.The heavier one will hit the ground first. 2.They will hit the ground at the same time. 3.The lighter one will hit the ground first

Same objects. How does the acceleration of gravity compare? 1.The heavier one has a larger gravitational acceleration. 2.They have the same gravitational acceleration. 3.The lighter one has a larger gravitational acceleration

Same objects. How does the force of gravity compare? Be careful! 1.The heavier one has a stronger gravitational force. 2.They have the same gravitational force. 3.The lighter one has a stronger gravitational force

California Elementary School Science Standards for gravity From California Science Standards, hgih school a.Students know the relationship between the universal law of gravitation and the effect of gravity on an object at the surface of Earth.

Summary 1.Definitions: speed, velocity, acceleration 2.Differences between these three 3.Simple computations of speed & accel. 4.Gravity is an acceleration 5.All things freefall with same acceleration