Slide 1
Warm Up 4/18/12Calculate the speed for the following problems:If you walk to Northlake from JMMS it takes you 2 hours. If Northlake is 24 miles away, how fast could you get to the mall? Ms. Adeeyo drove from Durham to Charlotte after her aunts funeral. If she drove 110 miles for 2 hours how fast was she going? Announcements Test on Friday!I will show you your grades tomorrow.Are you ready for the EOGs?This year, your End of the Year assessment in science is the 8th grade science EOG (I will take off questions you have not learned yet). What happens if you pass? You will take honors science class next year
Think and Write 10 minutes Ms. Adeeyo will show you several documents that are very important to her. Will your teachers write good recommendation letters for you one day? Why or why not?What can you do now to prepare yourself for the future? Velocity and AccelerationSpeed it up!
What is velocity? Velocity is a speed in a specific direction.Velocity gives both the speed and direction of the objects motion.
You should have this in your notes. If you dont or cant remember, write it down. AccelerationAcceleration is a change in velocityCheck for UnderstandingWhat two components make up velocity?
VelocitySpeedDirection
Check for UnderstandingAccelerationDef.: Change in _________Can be change in speed or direction (speed up, slow down, or change direction)Check for UnderstandingIs this ball accelerating?
Yes! Because the direction is changing.Which cars are accelerating?
Cars B and C!ABC
AccelerationAcceleration is not just a change in velocity, its how fast that change happens.
Which car has the greatest acceleration?
Car C!ABC
AccelerationTo measure it, you must know the initial velocity, the final velocity, and the time it takes to make the change.
AccelerationDef.: Change in velocityCan be change in speed or direction (speed up, slow down, or change direction)Acceleration = v/ tAccelerationInitial Velocity Objects velocity when you start measuring acceleration.Final Velocity Objects velocity when you finish measuring acceleration. - Greek letter delta change
AccelerationAcceleration = change in velocity timea=vtThe unit for acceleration is m/s2.Accelerationv is the difference between the final velocity (vf) and the initial velocity (vi).v = vf - vi
AccelerationDef.: Change in velocityCan be change in speed or direction (speed up, slow down, or change direction)Acceleration = v/ tv = vf viExample 1A roller coasters velocity at the top of a hill is 10m/s. Two seconds later it reaches the bottom of the hill with a velocity of 26m/s. What is the acceleration of the roller coaster?
Answervf = 26 m/svi = 10 m/s t = 2 sAcceleration = v/ ta = 26m/s 10m/s2 sa = 16m/s 2sa = 8m/s/s or 8m/s2Examples 2-4 Try them!2. A car travels at 60 miles per hour around a curve. Is the car accelerating?
3. A car travels in a straight line at 60 mi/hr. Is the car accelerating?
4. A car goes from 0 mph to 60 mph in 6 seconds. Whats the cars acceleration?Answers:1. Yes! Because its changing direction.2. No! Its not changing speed or direction.3. -vf = 60 mph vi = 0 mph t = 6 s-a = vf vi t-a = 60 0 mph = 10 m/s26 sGraphing Velocity vs. TimeConstant acc.No acc.Increasing acc.I think weve seen this beforeConstant speedNo motionIncreasing SpeedWarm Up 4/19/121. Why do you think a penguin slides/rolls further than a bear? AnnouncementsTest tomorrow! Sir Isaac NewtonBorn on December 25th, 1642 and died March 20th, 1727.Considered to be one (if not the) greatest and most influential scientist who ever lived.
Whats so great about him?Wrote a book about classical mechanics. Described universal gravitationThree laws of motion.Whys he important to us as 7th graders?We are studying motion currently and are beginning to learn about his three laws. Newtons LawsNewtons Laws are all about force and motion. Newtons 1st LawNewtons 1st Law: An object at rest will remain at rest and an object in motion will remain in motion unless an unbalanced force acts upon it. Newtons 1st Law Anytime you read about a situation where something is at rest and then it starts moving or is moving and then it stops, it is talking about Newtons 1st Law. Newtons 1st LawThere is a box that is sitting on the floor at rest. It will remain at rest until somebody pushes it.
At restIn motionNewtons 1st LawYou are driving in a car with no seat belt on. You see a family of ducks and slam on your brakes to avoid hitting them. Since you are not wearing your seat belt, you fly out of the car (remain in motion) until you hit the ground (an unbalanced force).
AHH! OuchIn motionAt restWarm Up 4/20/12What is the formula for speed?What is the formula for acceleration?How are the two different from each other?
Announcements Have a great weekend Test review (this looks very similar to your test)1. Meg and Emi left JMMS at the same time. Meg lives further away from the school than Emi, but they arrive at their houses at the same time. Compare their speeds. 2. Jaime and Clara are racing. Jaime runs 40 meters in 8 seconds. Clara travels 80 meters 20 seconds. Which runner is the fastest? Show your complete work using the speed triangle and label correctly!3. Tennessee Titans player, Chris Johnson takes 4.24 seconds to run a 40 meter dash. What is his speed? Show your work on the speed triangle and label.
More review Describe the acceleration as positive, negative, or zero.
Anymore questions? Speak now or forever hold your peace? Testing timeClear everything off your desk! Get out a sheet of notebook paper. DO NOT WRITE ON TEST SHEETS (Class set)Good luck
Warm Up 4/23/12Describe the difference between speed and acceleration? Why is it important for us to have final and intial velocities when calculating acceleration?Who is Sir Isaac Newton? What did he discover that was so important to science? Announcements Ms. Adeeyos birthday is tomorrow Please be sure that you are completing all homework assignments (I will place zeros for students that do not turn their assignments in)Sir Isaac NewtonBorn on December 25th, 1642 and died March 20th, 1727.Considered to be one (if not the) greatest and most influential scientist who ever lived.
Whats so great about him?Wrote a book about classical mechanics. Described universal gravitationThree laws of motion.Whys he important to us as 7th graders?We are studying motion currently and are beginning to learn about his three laws. Newtons Laws are all about force and motion.Newtons 1st LawNewtons 1st Law: An object at rest will remain at rest and an object in motion will remain in motion unless an unbalanced force acts upon it. Newtons 1st Law Anytime you read about a situation where something is at rest and then it starts moving or is moving and then it stops, it is talking about Newtons 1st Law. Newtons 1st LawThere is a box that is sitting on the floor at rest. It will remain at rest until somebody pushes it.
At restIn motionNewtons 1st LawYou are driving in a car with no seat belt on. You see a family of ducks and slam on your brakes to avoid hitting them. Since you are not wearing your seat belt, you fly out of the car (remain in motion) until you hit the ground (an unbalanced force).
AHH! OuchIn motionAt restWarm Up 4/20/12What is the formula for speed?What is the formula for acceleration?How are the two different from each other?
Announcements Have a great weekend Test review (this looks very similar to your test)1. Meg and Emi left JMMS at the same time. Meg lives further away from the school than Emi, but they arrive at their houses at the same time. Compare their speeds. 2. Jaime and Clara are racing. Jaime runs 40 meters in 8 seconds. Clara travels 80 meters 20 seconds. Which runner is the fastest? Show your complete work using the speed triangle and label correctly!3. Tennessee Titans player, Chris Johnson takes 4.24 seconds to run a 40 meter dash. What is his speed? Show your work on the speed triangle and label.
More review Describe the acceleration as positive, negative, or zero.
Anymore questions? Speak now or forever hold your peace? Testing timeClear everything off your desk! Get out a sheet of notebook paper. DO NOT WRITE ON TEST SHEETS (Class set)Good luck
Warm Up 4/23/12Describe the difference between speed and acceleration? Why is it important for us to have final and intial velocities when calculating acceleration?Who is Sir Isaac Newton? What did he discover that was so important to science? Announcements Ms. Adeeyos birthday is tomorrow Please be sure that you are completing all homework assignments (I will place zeros for students that do not turn their assignments in)Sir Isaac NewtonBorn on December 25th, 1642 and died March 20th, 1727.Considered to be one (if not the) greatest and most influential scientist who ever lived.
Newtons 1st LawNewtons 1st Law: An object at rest will remain at rest and an object in motion will remain in motion unless an unbalanced force acts upon it. Newtons 1st Law Anytime you read about a situation where something is at rest and then it starts moving or is moving and then it stops, it is talking about Newtons 1st Law. Newtons 1st LawThere is a box that is sitting on the floor at rest. It will remain at rest until somebody pushes it.
At restIn motionNewtons 1st LawYou are driving in a car with no seat belt on. You see a family of ducks and slam on your brakes to avoid hitting them. Since you are not wearing your seat belt, you fly out of the car (remain in motion) until you hit the ground (an unbalanced force).
AHH! OuchIn motionAt restInertia This is defined as the resistance of an object to change in speed or direction of its motion. Thus, Newtons first law is also called the law of inertia. When you measure the mass of an object, you are also measuring its inertia. For example, there is less resistance when lifting an empty box than a box full of stuff. Therefore, there is more inertia in the box full of stuff. Friction This is a force that resists the motion between two surfaces in contact. The resistance depends on the type of surface that are in contact. For example, there is less frtiction between hardwood floors and roller skates than roller skates and gravel. Independent practice (you may use your notes) What is the relationship between force and motion as seen by Newtons first law?What is inertia? How is the inertia of an object related to its mass?Once a baseball has been hit into the air, what forces are acting upon it? How can you tell that any forces are acting upon the ball?
