Presentation on theme: "Is she moving clockwise or"— Presentation transcript:
1 Is she moving clockwise or Topics CoveredMotion Distance Displacement Speed Velocity Calculating speed and velocity Distance/Time graphWhat is motion? How can two people see the same object but only one person describe the object as moving? How can you tell if something is moving? Can you determine the speed of moving objects?Lets find out……..Is she moving clockwise orcounterclockwise?Explain the concepts that motion can be an illusion and we cant always believe our eyes.Explain the concept that the first and the third image are not moving at all and the movement of the second image is dependent upon the viewer.Explanation of the spinning woman can be found at:
2 Are the blue dots moving? Explain to the students that it may appear to be moving but the object isn’t actually moving at all that it is an illusion. Once the students focus on one dot for a few seconds the apparent motion will appear to stop to signify that none of the dots were moving to start with.At first it may appear that the blue dots are moving. Find a blue dot and concentrate only on that dot. Does everything appear to stop? Was anything even moving to begin with?
3 Relative MotionTo describe motion we can ask, “has the object changed positions?”In order to explain motion accurately you must first have a frame of reference aka reference point.Frame of reference-objects not moving in relation to one another.Relative motion- movement in relation to a frame of reference.What is moving in this slide, the bow or the violin? In which direction is the object moving? Which of the two would be the frame of reference?Note: all Vocabulary terms are in red text and all SI units are in blue text.Ask students to answer the questions posted on the slide and open up room for discussion on this topic.You can also move around your classroom as you teach this material and ask students how do they know you are moving and encourage them to use the terms in red from this slide. Also have them to identify some frame of references in the classroom that could be used to describe your motion as you move throughout the classroom.
4 Distance vs Displacement Lets think about it………Displacement will always be equal to zero when the object return to its starting positionIf the distance is the total path travelled and the ambulance went east 50m then north 30m then back west for 50m then I would simply add the three paths together to get the distance50m+30m+50m=130mDistance is the length of a path between two or more points (total path travelled)Displacement is the length from the starting point to the ending point (shortest route from start to finish)SI (Standard International) Unit= (m) MetersWhat is the total distance travelled by the ambulance?What is the displacement?And if the displacement is the shortest path from start to finish then the displacement will be equal to30mWhen covering displacement for two lengths make sure to review Pythagoras theorem to find the unknown length. Also emphasize that when a moving object returns to its original location that the displacement is equal to zero. You may also want to introduce the concepts of SI units and the importance of using them correctly.130 m30 m
5 Distance vs Displacement Practice 9 km3 km1. A truck travelled 6 km to the East turned around and travelled 3 km back to the West.Distance?Displacement?2. A truck travelled 6 km to the East turned left and travelled 4 km to the North.Displacement? (Hint: Use Pythagoras theorem to find the unknown side of a triangle)3. If an object starts and stops at the same position what is the displacement?10 kmThis would be a great opportunity for guided practice to help walk the students through the practice problems. A great method is to have the students to write out what is given, what formula is needed to solve, substitute the given information into the formula, and then the answer with the correct the problem.7.2 km
6 SPEED How do you know how fast something is moving? You need two things to figure out how fast something is moving.Think about the speed limit sign which is mphWhat two things are being considered here? Distance and Time (SI Unit for time = (s) secondsYou can think of various things that you can calculate the speed of in your classroom to do a demonstration during this time. I often throw a ball across the classroom to a student to catch. while having another student to time it (most students have cell phones with stop watches so you can incorporate technology into the lesson) I then have students to measure the distance from me to the other student. They then use the data they have collected in order to calculate the speed of the ball. You can also do this with toy race cars, paper airplanes, walking or running around the track, etc.
7 Speed Vs VelocitySpeed is how far something travels in a given amount of time. It only indicates a numerical value. We say that it is a scalar quantity.Scalar= a quantity that has magnitude onlyExample 55 mphVelocity (V) = the speed & direction an object is moving. We say that it is a vector quantity.Vector= a quantity that has magnitude & directionExample: 55 mph westHeavily emphasis that velocity includes direction while speed does not.
8 VectorsVectors can be indicated by an arrow. The length of the arrow indicates the magnitude, the point of the arrow indicates the direction.Figure 1Figure 2Figure 1 indicate two objects moving in opposite direction with the same magnitudeFigure 2 indicate two objects moving in the same direction, however object B has a greater magnitude than object A.
9 Calculating Speed and Velocity Speed is the ratio of the distance (d) an object moves to the amount of time (t) it takes to get there.SI unit is m/s (meters per second)This would be a great opportunity for guided practice to help walk the students through the practice problems for calculating speed. A great method is to have the students to write out what is given, what formula is needed to solve, substitute the given information into the formula, and then the answer with the correct the problem.Example: Given Formula Substitution Answer & UnitD=50m V=D/T V=50m/6.5s m/sT=6.5sIf a student ran the 50m in 6.5s what is their average speed?V=D/T V=50m/6.5s V=7.69m/s
10 Average Speed Vs Instantaneous Speed Average speed - computed for the entire duration of the trip (total distance divided by total time)Instantaneous speed = measured at a particular instant (selected distance divided by corresponding time interval)Look at the graph to the right and determine:Average Speed=Instantaneous speed at 5 meters=Have students to calculate speed using data taken from a graph above. If you see students are having a hard time reading a graph you may want to give them some graphing reinforcement assignments for them to review the concepts of graphs.1 m/s0.625 m/s
11 Speed and Velocity Practice Mary went on a trip to the beach. She traveled 45 kilometers North in 0.5 hour, followed by 63 kilometers North in 0.7 hour. What was her average velocity?The cross country team runs 5 kilometers in 48 minutes, then 3 kilometers in 36 minutes, and finally 1 kilometer in 16 minutes. What is the average speed for the cross country team in kilometers per minute?If an Olympic swimmer can swim at an average speed of meters per second during a 50 meter race, what will their finishing time be?90 km/hr North0.09 km/minNow would be a great opportunity to wrap up the lesson by practicing some additional problems. This is the opportunity to assess student learning in various ways. You may want to do the questions as a game offering incentives to students who get them correct or the first to get it correct. You may also make it a quiz or you may take it up as an exit ticket.23.1 s
12 Quick Review What is a reference point? What is the SI unit for speed and velocity?What two things do you need to calculate speed?What is the difference between speed and velocity?An object that is not moving in relation to anotherMeters per second (m/s)This is the opportunity to assess student learning in various ways. You may want to do the questions as a game offering incentives to students who get them correct or the first to get it correct. You may also make it a quiz or you may take it up as an exit ticket. I use a reward system called big bucks and I always pass them out at the end of my lessons during the review questions. It is a great way to increase class participation.Distance and TimeSpeed is a numerical value alone and velocity indicates a numerical value and a direction.