1. Monday 10-1
Physical Science

2. Do Now Write the 3 laws of motion
Use the 2nd law to find the net force applied to a 5 kg object to make it accelerate 10 m/s2

3. Answers
1st law: Objects at rest will stay at rest, objects in motion will stay at the same rate, unless acted upon by a net outside force
2nd law: Fnet = ma
3rd Law: For every action, there is an equal, but opposite reaction
F = ma = (5)(10) = 50 N

4. Today Homework Hand in pages 852, 857 if you have not already
Get help outside class before
Free-Body Diagrams
Auto accidents and physics
“Jaime’s Mishap with the Bus” yellow workbook, handout and introduction

5. Free Body Diagrams
Represent the object by a simple geometric shape or a dot
Represent all forces on that object by arrows that originate from shape/dot
Only represent the forces that are applied to the object, NOT forces the object applies to other things

6. The forces on a Kitty Cat

7. Fground
Fgravity or Fweight

8. What would be the free body diagram of …..
What are the forces on the dog?

9. Answer Reactive force of ground
Applied force of ground pushing paws forward
Force of leash
Dog
Weight of dog

10. Create a free-body diagram of one of the dancers

11. Create a free-body diagram of the ball

12. Draw a free-body diagram of the rock climber

13. Have you been in an auto accident?

14. In 2004, there were over 42,000 deaths involving automobiles and between 3-6 million injuries in the United States

15. There may be as many as 750,000 million deaths and million injuries resulting from auto-accidents worldwide per year

16. What are the ways people get hurt if they inside the autos during the accident?

17. Be thrown through windshield
Crushed
Injured by steering wheel, or dashboard
Injured by loose material in car
Injured by objects outside of cars

19. Frontal accidents Which way does the person travel after impact?
How about stuff on the seat?
How about stuff in the person’s hands?

20. Can you explain, using Newton’s Laws why the face is against the air bag instead of the headrest?

21. Rear accidents
Which way does a person’s head go upon impact from behind?
What would happen to the head without a headrest?
Should the airbag deploy in a rear-end collision?

23. How does speed relate to auto accidents?

24. At low speeds

25. At somewhat higher speeds

26. How does speed relate to force?

27. Does it matter the size of the vehicles that crash together?

29. How would you describe the amount of damage to the bus and the car?

30. Do Now Problem
Bobby was standing by the road the other day and was run into by a 4 year old on a tricycle. If the 20 kg toddler and his
5.3 kg bike produces a force of 490 N on Bobby, what is the rate at which the bike slows down.

31. Answer F = -490 N (Third Law) Mass = 25.3 kg
A = Fnet / mass = (-490) / 25.3
A = ________

32. Hand out Yellow Workbooks
Read pages 2 and 3
Answer questions
What are the answers to question on page 2?

33. What are the factors that determine how fast a car comes to a stop?

34. Some Factors that determine rate at which a car stops
Road conditions
Tire condition
Brake Conditions
Weather
How distracted the driver is
How tired the driver is
If the driver is under the influence

35. Can you catch a dropped dollar?

36. Reaction Time
There is always a delay between seeing an occurrence and reacting to it

37. What of the previous factors are influenced by the driver?

38. Driver influenced conditions
Condition of the car
Condition of the driver
Rate at which the car moves

39. How close should you to another vehicle on the road?

40. How far apart should vehicles be driving down the road?

41. The rules
The 2 second rule
The 1 car length for every 10 mph rule

42. Pg 14
Read
Answer the 2 questions

43. X-rays, EKG tests X-rays See if there is any internal damage to bones
MRI – see if there is any damage to soft tissues
EKG
See if there is any thing wrong with the heart, or circulation

44. Crash Simulation I Part A: What happens to the passengers in Car?
Part B: What happens to the passengers in the bus?

45. Procedure
Form Groups
Each group will need to make the person in the car and the heads of the people on the bus
Perform experiment as indicated
Make observations
Answer questions in book on pg 15-16

46. Answers for page 852, 857 homework
# 3 4,989,000 cm
# m/s > m/s, yes
# m/s2
# s
# N
# m/s2
# N
# m/s2
#95 65 kg

47. Do you need seatbelts on a bus?
Write a paper listing at least 3 reasons for having seat belts and 3 reasons for not having seat belts.
Connect all of Newton’s laws to support your reasons
Determine your answer to the above questions
Turn in to me on Tuesday of next week