1. Aim: How do we use the kinematics formulas? Do Now: What is the difference between average velocity and instantaneous velocity? Quiz Tomorrow

2. On the back of your reference table You can find the two formulas we have been using so far to find the average velocity or speed and average acceleration. You can also find the 3 new kinematics formulas.

3. New Kinematics formulas v f = v i + at d=v i t+ ½ at 2 v f 2 = v i 2 + 2ad vf= final velocity vi = initial velocity a= acceleration t= time d= distance

4. Initial vs. Final velocity Initial velocity is the starting velocity of an object. Final velocity is the velocity reached at a later point in time.

5. Acceleration The change of the object’s velocity over time. Recall that acceleration is the final velocity – the initial velocity / time.

6. Example A car accelerated from rest to 25m/s. What are the initial velocity? Final velocity? Acceleration? If it traveled for 15s what distance did it cover?

7. Example Answers Initial velocity: car stated from rest. V i = 0 m/s Final velocity: The problem states to 25m/s  V f Acceleration = (25m/s – 0m/s )/ 15s = 1.666666 m/s 2 = 1.7m/s 2

8. Solving for distance by GUESS method Given: vi = 0 m/s, vf = 25 m/s t= 15 s a= 1.7 m/s 2 Unknown: distance = ??? Equation : d=v i t+ ½ at 2 Substitute: d= (0m/s)(15s)+ ½ (1.7m/s 2 ) (15s) 2 Solve: d= ½ (1.7m/s 2 ) 225s 2 = 191.25m = 190m

9. Distance vs. Displacement The distance: the path covered by the object as it traveled The displacement is how far the object moved from start to finish.