Presentation on theme: "Vocab (Leave room for definitions) Position (x) Displacement (∆x)= (x f -x i ) Distance (d) Delta (Δ) – The symbol used to define change Final."— Presentation transcript:
Vocab (cont.) Reference Point Reference Frame Veloctiy (v) Speed (s) At Rest What is the difference between speed and Velocity?
Scalar vs. Vector A scalar is a quantity with only magnitude. Magnitude = Size A vector is a quantity with both magnitude and direction. Speed is a scalar and Velocity is a vector. How does this make them different?
Speed – Distance over time (Scalar) Instantaneous Velocity – The rate of change in position displacement over time v = velocity x = position t = time
1.What is the van’s position at 10 sec? at 40 sec? 2.At what position does the van start? 3.What is the distance traveled between 40-50 sec? 4.What is the displacement between 40-50 sec? 5.What is the distance traveled between 0-70 sec? 6.What is the displacement between 0-70 sec?
1.When is the van moving forward? 2.When is the van moving backwards? 3.When is the van at rest? 4.When is the van traveling the fastest?
1.Make a table of time and position for every 10 seconds. 2.Find the slope for each 10 second interval starting with 0- 10 sec. time (sec)position (m)time (sec)position (m) 05 105 2010 3012.5 4015 50-5 60-5 700 time (sec)position (m) 0-100 10-20.5 20-30 30-40 40-50 50-60 60-70
1.Make a graph of this table. time (sec)position (m) 0-100 10-200.5 20-300.25 30-400.25 40-50-2 50-600 60-700.5
Average Speed/Velocity Avg. speed=Total distance over total time.
Practice problems 1. A person runs 2 m/s for 1 min and then 8 m/s for one min. What is her average speed? 2. A car travels 50 km in one hour and 100 km in one hour. What is the average speed in km/hr?
3. A cyclist rides 5.00 m/s for 2000. meters and then 15.0 m/s for 2000. meters. What is the cyclists average speed in m/s? 4. A horse runs 1000. meters at 20.0 m/s west. How fast must the horse run east for 1000. meters to make his average speed 40.0 m/s?
What is velocity? (What is it actually telling you) How does this relate to the units of velocity? What do they mean? m/s, mi/hr, km/hr Now describe 35 m/s. How about 65 mi/hr
More examples (don’t forget to leave room for your work) 1. If a mouse scurries 1.5 m/s for 2.00 min, how far has the mouse scurried? 2. If the same mouse scurries 3.5 m/s, how long (sec) will it take her to travel 1.00km? How many minutes is this? 3. If a cat has only 2.00 min to travel 0.75 km to catch the mouse, how fast must the cat run in m/s?