1. Displacement, Time, and Velocity

2. Distance vs Displacement
Distance – the total amount traveled.
Displacement – the total amount displaced from the starting point.

3. Organize the Information Sketch the scene Verify Units
Solving Problems
Organize the Information
Sketch the scene
Verify Units
Consider Your Formulas
Solve

4. Distance vs Displacement
Practice problem 1 A car travels 120 m north, then 30 m south, then finally 60 m north. What is the distance the car traveled? d = 120 m + 30 m + 60 m = 210 m What is the displacement of the car? Δx = 120 m + (-30 m) + 60 m = 150 m

5. Distance vs Displacement
Practice Problem 2 Janice drives her scooter 7 km North. She stops for lunch then drives 5 km North again. What distance did she cover? 12 km What was her displacement?

6. Distance vs Displacement
Practice Problem 3 Anthony walks to the pizza place or lunch. He walks 1 km East, then 1 km South and then 1 km east again. What distance did he cover? 3 km What was his displacement? 2.2 km

7. Distance vs Displacement
Practice Problem 4 On his fishing trip Justin rides in a boat 12 km South. The fish aren’t biting so they go 4 km west. They then follow a school of fish 1 km North. What distance did he cover? 17 km What was his displacement? 11.7 km

8. Time
Time is measured in many ways, years, days, hours, minutes, and seconds just to name a few. When we divide distance or displacement by time we end up with speed or velocity. Some examples are mph, kph, and m/s.

9. Time
In physics we almost always use seconds for our calculations. 1 year = s 1 day = s 1 hour = 3600 s 1 minute = 60 s

10. Speed vs Velocity
Average speed is calculated by dividing the total distance by the elapsed time. Speed = distance/time Average velocity is calculated by dividing the total displacement by the elapsed time. 𝑉 𝑎𝑣𝑒. = Δ𝑥 Δ𝑡 Because the car go around a circular track their displacement is 0 m. What is their ave. velocity?

11. Speed vs Velocity
Practice Problem 1 During your vacation you travel 500 km in 5 hours to your destination. You then travel another 500 km in 5 hours on the return trip. What is the average speed? Speed = distance/time = 1000km/10hours = 100kph What is the average velocity? 𝑉 𝑎𝑣𝑒. = Δ𝑥 Δ𝑡 = 500 𝑘𝑚+(−500 𝑘𝑚) 5 ℎ+5 ℎ = 0 𝑘𝑚 10 ℎ =0 𝑘𝑝ℎ

12. Speed vs Velocity
Practice Problem 2 A car travels 120 m North, then 30 m South, then finally 60 m North. It does this in 120 s. What is the average speed? Speed = 210 m/120s = 1.75 m/s What is the average velocity? 𝑉 𝑎𝑣𝑒. = Δ𝑥 Δ𝑡 = 120 𝑚+ −30 𝑚 +60 𝑚 120 𝑠 = 150 𝑚 120 𝑠 =1.25 𝑚 𝑠

13. Speed vs Velocity
Practice Problem 3 Anthony walks to the pizza place or lunch. He walks 1000 m East, then 1000 m South and then 1000 m east again. He does this in 30 mins. What is the average speed? Speed = 3000 m / 1800 s = 1.67 m/s What is the average velocity? 𝑉 𝑎𝑣𝑒. = Δ𝑥 Δ𝑡 = 2200 𝑚 1800 𝑠 =1.22 𝑚 𝑠

14. Speed vs Velocity
Practice Problem 4 On his fishing trip Justin rides in a boat m South. The fish aren’t biting so they go 4000 m west. They then follow a school of fish 1000 m North. This is done over 2 hours What is the average speed? Speed = m / 7200 s = 2.36 m/s What is the average velocity? 𝑉 𝑎𝑣𝑒. = Δ𝑥 Δ𝑡 = 𝑚 7200 𝑠 =1.63 𝑚 𝑠

15. Graphing Displacement vs Time
When graphing distance or displacement and time the displacement goes on the y-axis and the time goes on the x-axis. The slope of the line at any point will be the velocity.

16. Graphing Distance vs Time
Stationary
Moving toward start point
Moving away from start point
Moving toward start point
Stationary
Stationary
Stationary

17. Graphing Distance vs Time