1. How Far? _________ (d) ______________________________________ To get to the store go 2-miles east, turn right and go 3-miles south. How far will you travel to the store? __________________ Notes on Motion III How Fast. How Far & How Long

2. How Far? Units for distance are: English System _____________, ______________, ______________ Metric System _____________, ______________, ______________ In science the most common unit is: _______________

3. How Fast? Speed (v) _____________________________________________ Velocity (v) ______________________________________________ If you are traveling north at 65-mph. Your speed is : _________ Your direction is : ____________ Your velocity is : ____________

4. How Fast? Average Speed (v avg ) ____________________________________________ _____________________________________________ Average Speed is over a _______________. Instantaneous Speed (v) ___________________________________________ Your speedometer measures ____________________.

5. How Fast? Constant Speed (v) _______________________________________ Constant Velocity (v) _______________________________________________________ Can you have a constant velocity but not have a constant speed? Can you have a constant speed but not have a constant velocity?

6. How Fast? Units for speed and velocity: English System __________________, __________________ Metric System ________________________________________, _______________________________________ In science the most common unit is:

7. How Long? _______ (t) Units: __________, __________, __________ In science the most common unit is:

8. Solving Problems with Velocity and Speed In general the equation that relates the speed (or velocity) of an object to the distance it travels and the time it takes is: If we need to find the distance from speed and time, we use algebra to solve for d: If we need to find the time from distance and speed we use algebra to solve for t:

9. Solving Problems with Velocity and Speed We can use a triangle to help us remember these formulas.

10. Solving Problems with Velocity and Speed d vt Example Problem 1: A runner finishes the 100-m dash in 9.4-s. What is the average speed of the runner during the race? Know: Find: Formula: Solve:

11. Solving Problems with Velocity and Speed d vt Example Problem 2: A car travels with a constant velocity north of 45- m/s (100-mph). How far will the car travel in 300-s (5 minutes)? Know: Find: Formula: Solve:

12. Solving Problems with Velocity and Speed d vt Example Problem 3: The circumference of the Earth is approximately 40,000-km. How long would it take you to drive this distance at 320-km/hr? Know: Find: Formula: Solve: