Aim: What is the difference between speed & velocity?

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Date: 10/15/2007 Monday. Aim: What is the difference between speed & velocity?. Do Now: What is motion? Homework: Read pgs 70 – 73 in textbook & Answer Ques. 1 & 2 on pg 72 (Practice Problems) – Write out Formula, Plug in #’s, Calculate & Give Units. What is motion?. - PowerPoint PPT Presentation

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  • Aim: What is the difference between speed & velocity?Do Now: What is motion?

    Homework: Read pgs 70 73 in textbook & Answer Ques. 1 & 2 on pg 72 (Practice Problems) Write out Formula, Plug in #s, Calculate & Give UnitsDate: 10/15/2007 Monday

  • What is motion?A change in position over a certain amount of time or,

    The movement of an object

  • What is speed?The rate at which an object moves(how fast or slow)How can speed be calculated?Speed = Distance TimeSDT

  • 1) Carl Lewis runs a 100 meter race in 10 seconds. What is his average speed?Avg. Speed = Total distance/Total TimeAvg. Speed = 100 m/10 secAvg. Speed = 10 m/s

  • 2) How much time does it take for a cheetah to travel 84 meters at a speed of 28 m/s?Time = distance/speedT = 84 m 28 m/sT = 3 sec.

  • 3) What distance does a jogger go if she runs with a speed of 160 m/min for 20 minutes?Distance = speed x timeD = (160 m/min) (20 min)D = 3,200 m

  • What information does a Distance vs. Time Graph show?Smiths Trip to AlbanyDistance (km) Time (hr)501001502001234200

    150

    100

    501 2 3 4DISTANCE(km)TIME (hours)*Constant Speed:speed that stays the same

  • What information does a Distance vs. Time Graph show?Browns Trip to AlbanyDistance (km) Time (hr)1001001502001234200

    150

    100

    501 2 3 4DISTANCE(km)TIME (hours)*SpeedChanges

  • What is velocity?A measure of both speed & direction

    Example: An automobile travels 80 km Northin 2 hrs. What is the avg. speed of the car? What is the avg. velocity?V = D TV = 80 km 2 hrAvg. speed = 40 km/hrAvg. velocity = 40 km/hr North

  • Aim: 1. What does a distance vs. time graph show? 2. How do velocities add & subtract from each other?Do Now: 1. Take out homework. 2. What is the slope of a distance vs. time graph equal to?Homework: Handout (A Speedy Journey) Date: 10/28/2007 Friday

  • 20 km (40 km 20 km)0.5 h or 30 min40 km (80 km 40 km)1.5 hrs.

  • 5. What is car Bs avg. speed during the first part of this trip?Avg. S = T. Dist. T. TimeAvg. S = 40 km 0.5 hrAvg. S = 80 km/hr6. How fast did cars A & B go together?Avg. S = T. Dist. T. TimeAvg. S = 40 km 1 hrAvg. S = 40 km/hr

  • 12 km / 20 s = 0.60 km/s 20 km / 30 s = 0.67 km/s 30 km / 40 s = 0.75 km/s 56 km / 60 s = 0.93 km/s A = VF VItimeA = 0.67 0.60 10 .007 km/s2A = 0.93 0.75 20 .009 km/s2NO

  • Can velocities add together?Yes, but only if theyre moving in the same direction

    Example: If you are paddling a boat South at 5 m/s & the stream is moving at 8 m/s South:Are their velocitiesadding together?Your boat will move at:13 m/s South

  • Can velocities subtract from each other?Yes, but only if theyre moving in the opposite direction

    Example: If you are paddling a boat South at 10 m/s & the stream is moving North at 12 m/s:Your boat will move:2 m/s North

  • 6 m/s Right10 m/s Right16 m/s Right+-=10 m/s Right14 m/s Left4 m/s Left=What does each picture show?Velocities adding togetherVelocities subtracting

  • Aim: Lab: Measuring the Speeds of People WalkingDo Now: 1. Take out homework. 2. Read over lab 3. Answer ques. next slide.

    Homework: Complete LabDate: 10/17/2006 Wednesday

  • Aim: How can we calculate acceleration? Do Now: 1. Take out Lab & Motion Note-packet2. Complete Review Questions on pg 6 in your note-packet

    Homework:Handout

  • All 4 cars are moving at constant speedAvg. Speed = T. Dist./T. Time__________= 250 km/1 hr250 km/hr#1#4#1None

  • What is acceleration?The rate at which the velocity of a moving object increasesWhat is the mathematical formula for acceleration?Acceleration =change in velocity timeORa = vfinal vinitial t

  • 1) What is the acceleration of an ice skater who changes velocity from 5 m/s north to 15 m/s north in 5 seconds?a = 2 m/s2 Northa = vfinal vinitial t

    a = 15 m/s 5 m/s 5 s

  • 2) How quickly would a race car accelerate if its velocity changed from 0 to 32 m/s in 4 seconds?a = 8 m/s2a = vfinal vinitial t

    a = 32 m/s 0 m/s 4 s

  • What is deceleration?The rate at which the velocity of a moving object decreases

  • What information does a Velocity vs. Time Graph show?Smiths Trip to AlbanyVelocity (m/s) Time (s)7142128123428

    21

    14

    71 2 3 4VELOCITY(M/S)TIME (hours)*Constant acceleration

  • What is the motionof a freely fallingobject?Any object falling near the surfaceof the earth will accelerate at a rate of 9.8 m/s2 due to the pull of gravity.

  • Aim: What is Momentum?

    Do Now: Prepare for Motion Quiz

    Homework: Study for next weeks Exam on Motion & ForcesDate: 10/19/2007 Friday

  • Quiz (Motion)

  • What is momentum?The mass of an object multiplied by its velocity, which determines how difficult it is to stop the object.The greater the momentum = greater energy the object hasWhat is the mathematical formula for momentum?momentum = mass x velocity or p = mv

  • Aim: 1. What is Force?

    Do Now: 1. What 2 things does momentum depend upon?2. What are units of momentum?

    Homework: Study for a Quiz on Forces.Date: 10/22/2007 Monday

  • What is a Force?A push or a pull that one object exerts on another.Ex) A tow truck pulls a car, The wind pushes a flag, Gravity & FrictionWhat is a Newton?The unit used to measure forceForce = Mass X Acceleration1N = kg.m/sec2What are some examples of a force?

  • What is gravitational force?The attractive force between objectsDepends on the masses of the objects and the distance between themAs mass increases, gravitational pull increases

    As distance increases, gravitational pull decreases

  • 50 kg10 kgWhere is the Gravitational Pull the greatest?1.2.10 kg10 kg10 m10 m

  • 10 kgWhere is the Gravitational Pull the greatest?1.2.10 kg10 kg10 m20 m10 kg

  • What is weight?The weight of an object is equal to the gravitational force exerted by Earth (9.8m/s2) on an objectWhere will you weigh more: on theEarth or on the Moon? Why?

  • What are balanced forces?Forces on an object that are equal in size & opposite in directionThe net force is zero because the two forces cancel each other out-= 0

  • What are unbalanced forces?Unequal forces working against each other produces motion in the direction of the larger force. 10N4N-= 6N*In Opposite Directions,Forces Subtract

  • Aim: 1. What is Newtons First Law of Motion?

    Do Now: Prepare for a Quiz.

    Homework: Read pgs 98 103 & Ans. Ques. (1-4 & 6-7) on pg 103 (self-check)Date: 10/23/2007 Tuesday

  • Quiz (Momentum & Forces)

  • Newtons LawsMotion Jof

  • What is Newtons 1st Law of Motion?The Law of Inertia1. Objects at rest tend to stay at rest unless acted upon by an unbalanced force. 2. Objects in motion tend to remain in motion (in constant velocity, along a straight path) unless acted upon by an unbalanced force. (such as friction)

  • This is what happens when your not wearing a seatbelt. Since the car is in motion you are also in motion, and when the wall stops the car.You continue to be in motion and fly forward.

  • When the truck is stopped by the car. The ladder continues in motion.

  • What is inertia?The tendency of an object to resist a change in motion.Inertia is related to an objects mass: the more mass an object has the greater its inertia and the more difficult it is to change its motion.Which would have more inertia an empty shopping cart or a full one?

  • Aim: 1. What are 3 types of friction?Do Now: 1. Take out homework. 2. What is Newtons First Law of Motion?

    Homework: Read pgs 104-111 Ans. Ques. (1-4 & 6) on pg 111 (self check)

    Date: 10/24/2007 Wednesday

  • What is friction?Exists wherever 2 surfaces touch.Its a force that acts in the opposite direction to motion. It causes moving objects to slow down & stop.It always produces heat.

  • What types of friction are there?1) Sliding Friction When solid objects slide over each other.2) Rolling Friction Friction produced by wheels or ball bearings3) Fluid Friction The force exerted by a fluid (Lubricants such as grease & oil) change sliding friction into fluid friction and reduce the overall amount of friction.

  • What are some methods used to reduce friction?Can friction be good?Yes!Lubricants such as oil, grease, lotion, waterWheels (Rolling frictions is less than sliding friction)Sand on a smooth surface

  • PullRight 7N PullLeft 2N (Friction) In what direction is this object moving?What are 3 forces are acting on this object?How can we decrease the friction?What is friction?

  • Aim: How do force, mass & acceleration relate to each other?Do Now: 1. Take out homework.2. Describe the 3 types of friction.Homework: Study for tomorrows Quiz on ForcesDate: 10/25/2007 Thursday

  • What is Newtons Second Law?Force = Mass X AccelerationNewtons second law of motion explains how force and acceleration are relatedWhat is the equation form of Newtons second law?FMA

  • Which car will take a greater force to accelerate?

  • How much force is needed to accelerate a 1500kg car at a rate of 3 m/sec/sec?Force = mass x accelerationForce = 1500kg x 3 m/sec/secForce = 4500NFMA

  • A hockey player shoots a puck with a force of 900 Newtons. The puck has a mass of 1.5kg. At what rate will the puck accelerate? FMAAcceleration = Force MassAcceleration = 900 N 1.5 kgAcceleration = 600 m/s2

  • What is the relationship between force & acceleration?As force increases, acceleration increases.Direct Relationship

  • What is the relationship between mass & acceleration?As mass increases, acceleration decreases.Inverse Relationship

  • Aim: 1. What is Newtons 3rd Law of Motion? 2. Quiz on Forces.Do Now: Take out note-packet.Homework: Study for Tuesdays Motion/Forces ExamDate: 10/26/2007 Friday

  • What is Newtons Third Law of Motion?For every action there is an equal and opposite reaction.

  • Newton's third law. The skaters' forces on each other are equal in magnitude, and in opposite directions

  • Newtons Final Quiz

  • STOP

    Quiz Section Beyond This Point

  • Quiz (Motion))1. Velocity = ________ & ________.2. A change in position over time is known as _________.3. If I rollerblade 10 meters in 2 seconds, how fast am I moving?If a car goes 20 km/hr in 0.5 hours how far did it travel?A car went from stop to 30 m/s in 5 seconds. What was the rate of acceleration?GO ON.

  • These graphs show:6.

    7.GO ON.

  • Which car is moving the fastest?

    What pulls everything towards the earth at a rate of 9.8 m/s2?

    What tools are used to calculate speed? Stop!!

  • Quiz (Momentum &Forces))1. Momentum = ________ & ________.2. A force = a ________ or a _________.3. Units of force = ______________4. As distance increases, gravitational pull ___________.A book is resting (no motion) on the desk & is pushing down with a force of 3N. The desk is pushing up with a force of ________N.

    STOP!!

  • What is a force?What are balanced forces?What do unbalanced forces cause?What does friction create?A force gives off ?What are units of force?What is a force that opposes motion? STOP!!!