Measuring Motion Understanding Speed , Velocity , and Acceleration

1. Measuring Motion Understanding Speed, Velocity, and Acceleration

2. Measuring Motion SPEEDrate at w/c an object moves Distance (D) Speed = Time (T)

4. CONSTANT SPEED SPEED THAT DOES NOT CHANGE

5. CONSTANT SPEED

6. SAMPLE PROBLEM: At what speed did a plane fly if it traveled 1760 meters in 8 seconds?

7. STEPS IN PROBLEM SOLVING • STEP 1. Write the formula • STEP 2. Substitute given numbers and units • STEP 3. Solve for the unknown.

8. SOLUTION Step 1.Speed = Distance/Time Step 2. Speed = 1760 meters/ 8sec Step 3. Speed = 220 m/sec

9. SAMPLE PROBLEMS: 1. A car travels 240 kilometers in 3 hours. What is the speed of the car during that time? ANSWER: S= d/t S= 240 km/3 hr 80 Km/Hr

10. The speed of a cruise ship is 50 km/hr. How far will the ship travel in 14 hours? Answer: D = ST 700 km

11. AVERAGE SPEED TOTAL DISTANCE / TOTAL TIME AVERAGE total distance traveled SPEED time =

12. AVERAGE SPEED

13. A car travels 200 m in 10 seconds. What is the average speed of the car? ANSWER: Ave speed= total d/total time = 200m/10s 20 m/s

14. Definitions: A change in position in a certain amount of time is __________. __________________ is the rate at which an object moves and is determined by dividing ____________ by _____________. _________________________ is speed that does not change. _________________________ is calculated by dividing the total distance by the total time.

15. Image source: http://www.myteacherpages.com/

18. Velocity • The speed and direction of an object’s motion. • 88 km / hr southwest Image source: http://www.myteacherpages.com/

19. VELOCITY SPEED IN A GIVEN DIRECTION d V = t direction

20. A bird flies south at 20 m/s. • SPEED = 20 m/s • VELOCITY = 20 m/s south

21. A tropical disturbance spotted east of the Philippines was moving at 60 km per hour at a Northwesterly direction and having maximum sustained winds of 150 km/h? What is the storm’s velocity? • Given: S= 60km/h T= 10s dir= NW • Formula V= d/t with dir • Work/Answer V= 60km/h NW

22. CONSTANT VELOCITY

23. CHANGING VELOCITY

24. Exploring Acceleration Finish Start Are you speeding up, slowing down, or moving at constant velocity? 0m 5m 10m 15m

25. ACCELERATION Rate of change in velocity Final velocity – Original Velocity Time A= Change in velocity divided by the time during which this change occurs

27. A roller coaster’s velocity at the top of the hill is 10 m/s. Two seconds later it reaches the bottom of the hill with a velocity of 26 m/s. What is the acceleration of the roller coaster?

28. SOLUTION: Final Velocity – Original Velocity Time A= 26 m/s- 10 m/s 2 s 16 m/s 2 s A= A= A= 8 m/sec/sec

29. DECELERATION • decrease in velocity • negative acceleration • slows down

30. A car accelerated from 0 m/sec to 30 m/sec in 10 sec. What was the rate of acceleration? 3 m/sec/sec

31. A roller coaster is moving at 25 m/sec at the bottom of a hill. Three sec. later it reaches the top of the next hill, moving at 10 m/sec. What is the deceleration of the roller coaster? - 5 m/sec/sec

33. CIRCULAR MOTION • Velocity is continuously changing • Object is accelerating even with constantspeed.

34. MOTION GRAPHS

36. A train accelerated from 5 km/hr to 55 km/hr in 0.5 hr. What was the rate of acceleration? 100 km/hr/hr

37. http://www.youtube.com/watch?v=Uy3nATe85Kg&feature=related Gravity and acceleration

39. http://www.youtube.com/watch?v=_BM89yVZoBg Eureka video- Measuring Acceleration

40. ACCELERATION • TELLS HOW FAST IT IS MOVING • SHOWS HOW FAST VELOCITY IS CHANGING • HAS DIRECTION SPEEDING UP SLOWING DOWN CHANGING DIRECTION