1. What are the results for following indicators in the presence of acid, neutral and base? Litmus A – Blue & Red change to Red N – Blue & Red do not change B – Blue & Red change to Blue Bromthymol Blue A – Yellow N – Green B – Blue Warm-up

2. 6-2 Distance & Displacement Identify appropriate SI units for measuring distances. Distinguish between distance and displacement. Calculate displacement using vector addition.

3. Measure Distance Distance is the measure of length of any path between two points. The path can be a straight line. Not always Use the unit best suited for the distance: Very large distance – km Mississippi River is 3780 km long. Very small distance – cm or mm The distance a marble rolls on carpet – 6 cm Distances in between could be hm, dkm, m, or dm.

4. Symbols d – distance d1 , d2 Δx , Δy , or r – displacement xi , xf , yi, and yf m – meters m – mass

5. Vector vs. Scalar Vector Any quantity that has magnitude (size), units, and direction Scalar Any quantity that has only magnitude (size), and units, but direction does not matter.

6. Distance vs. Displacement Distance is the length of any path between two points. d = |x1| + |x2| Displacement is the direction and straight line distance between starting point and finishing point. ∆x = x1+ x2 ∆y = y1+ y2 For right triangles r = √( x2 + y2) Sign & direction are important!!!

7. Practice A football player runs 25 meters up-field and is pushed back 3 meters when he is tackled. What is the player’s distance traveled and displacement?

8. Practice A pitcher throws a baseball 20 meters to the catcher and the catcher throws the ball back to the pitcher. What is the distance traveled and the displacement of the ball?

9. Practice The Lone Ranger runs 5 meters east to get away from the bad guys, but he stops when he sees more bad guys and runs 12 meters west to hide behind a rock. What was his displacement and total distance traveled?

10. 6-2 Summary What is the difference between distance and displacement? How do you find displacement? When do you use Pythagorean theorem?