2 What is Motion?Motion: A change in position of an object compared to a reference point Motion involves all of the following: You fill in the blank!
3 Event that involves a change in the position or location of something. Definition of MotionEvent that involves a change in the position or location of something.
4 Motion is RelativeRelative – it is described or compared to a REFERENCE POINTExample: Are you moving at this moment? If yes, then how are you moving?How does your movement look to another person? (Can they tell you are moving?)
5 Displacement vs Distance Fgjflgjkfdlgjflgjkdflg vxcvxcbcvbcvbcjDisplacement the distance and direction of an object’s change in position from its starting pointDistance – how far something moves
6 Displacement vs Distance Displacement the distance and direction of an object’s change in position from its starting pointDistance – how far something moves
7 What is the Displacement? Problem - A physics teacher walks 4 meters east, 2 meters south, 4 meters west, and 2 meters north.What is the total displacement of the teacher?What is the total distanced walked by the teacher?
8 And the answer is...Displacement = 0 m - The teacher has returned to the starting point.Distance = 12 metersThe distance is 12 meters but the displacement is zero. The teacher has “covered 12 meters on the ground”, yet when he is finished walking, he is not walking out of place.
9 Types of Motion Uniform motion - constant speed in a straight line Accelerated motion – motion that is changing in speed or directionCircular motion - speed is constant but the direction of motion is changing continuously
10 The rate of change in position What is Motion?SpeedThe rate of change in positionSpeed = distance ÷ time orSpeed = distancetime
11 Speed Types of SpeedAverage SpeedInstantaneous SpeedConstant Speed
12 Comparison of time and distance Speed Average SpeedComparison of time and distanceDistance traveled per unit timeDistance is referring to "how much ground an object has covered" during the time it was in motion.S = d / tT = d / sD = s x t
14 Speed that does not change Speed Constant SpeedSpeed that does not changeInstantaneous speed that does not changeExample: After setting cruise control on a car, your speed at any point will be the same until you turn off the cruise control.
15 Velocity What is Motion? Speed plus direction Example: 50 km/hour north
16 VelocitySpeed AND direction -- Velocity must include a speed and a direction.Displacement is "how far out of place an object is because of its motion”. Displacement is the object's change in position.
18 Acceleration What is Motion? The rate of change in velocity Positive acceleration = speeding upNegative acceleration = slowing down (decelerate)Acceleration = Vfinal – VinitialTime orAcceleration = ∆VelocityTime
19 Acceleration "the rate at which an object changes its velocity Acceleration "the rate at which an object changes its velocity." An object is accelerating if it is changing its velocity.
20 Acceleration A change in velocity Speeding up Slowing down Positive accelerationSlowing downNegative accelerationDecelerationChanging direction
21 The Direction of Acceleration Acceleration will always have a direction associated with it. The direction of acceleration depends on two things:whether the object is speeding up or slowing downwhether the object is moving in the + or - direction
22 Circular Motion: Continuous Acceleration An object traveling in a circular motion is always changing its direction. Therefore, its velocity is always changing, so it is accelerating. This is known as centripetal acceleration.
23 200m/40s = 5 m/s2 km/1000s = km/sor 2 m/s200m/40s = 5 m/s2 km/ 1000s = km/s100m/10 m/s = 10 s50 m/s x 20 s = 1000m100 m/10 m/s = 10s50 m/s x 20s = 1000 m20,000 m/ 40 m/s = 500 s
24 10m/20s = 0.5 m/s40 m40m/40s = 1m/s25m/10s = 2.5 m/s Steepest line