1. Forces and Motion Notes
4/27/2015

2. IMPORTANT FORMULAS TO KNOW:
SPEED(m/s) = DISTANCE(m) / TIME(s)
VELOCITY(m/s) = DISPLACEMENT(m) / TIME(s)
ACCELERATION(m/s2) = VELOCITY(m/s) / TIME(s)
FORCE(Newton) = MASS(kg) * ACCELERATION(m/s2)
WORK(Joule) = FORCE(Newton) * DISTANCE (m)

3. SPEED SPEED = DISTANCE / TIME
Constant Speed on a graph of x = time, y = distance:
Average Speed = speed average for whole length of time
SLOPE = RATE
Rate at which distance is covered
SI unit is meters/second (m/s)

4. VELOCITY VELOCITY = DISPLACEMENT/TIME
Change in position in a given direction over time
Directions: (North, South, East, West, Towards, Away)
Can be represented by arrows (vectors)

5. ACCELERATION ACCELERATION = VELOCITY/TIME
SI Units (m/s)/s simplified to become m/s2
Change in velocity over time
Gravity is an acceleration: 9.8m/s2

6. NEWTON’S LAWS Law #1 (law of inertia)
An object in motion will stay in motion and an object at rest will stay at rest UNLESS an unbalanced force acts on it

7. NEWTON’S LAWS
Law #2 (law of action) FORCE = MASS * ACCELERATION (F=ma)
An object that has an unbalanced force acting on it will accelerate in that direction of that force
SI Unit of FORCE is NEWTON
SI UNIT of MASS is kilogram kg
SI UNIT of ACCELERATION m/s2
8 N
6 N

8. NEWTON’S LAWS Law #3 (law of reaction)
Forces always occur in equal and opposite pairs. For every action there is an equal and opposite reaction

9. Work WORK = FORCE * DISTANCE SI Unit: JOULE
One joule of work is done when
A force of one Newton moves an object through a distance of one meter in the same direction of the force

10. Which of Newton’s Laws does the following best describe?
1. A golfer swings the clubs and hits the golf ball to the green.

11. Which of Newton’s Laws does the following best describe?
1. A golfer swings the clubs and hits the golf ball to the green.
2nd Law!!!

12. Which of Newton’s Laws does the following best describe?
2. The Earth revolves around the sun about every 365 days.

13. Which of Newton’s Laws does the following best describe?
2. The Earth revolves around the sun about every 365 days.
1st Law!!!

14. Which of Newton’s Laws does the following best describe?
3. A boat pulls a skier across a lake.

15. Which of Newton’s Laws does the following best describe?
3. A boat pulls a skier across a lake.
2nd Law!!!

16. Which of Newton’s Laws does the following best describe?
4. A plate stays on the table as the table cloth is ripped off.

17. Which of Newton’s Laws does the following best describe?
4. A plate stays on the table as the table cloth is ripped off.
1st Law!!!

18. Which of Newton’s Laws does the following best describe?
5. A person walks up the stairs.

19. Which of Newton’s Laws does the following best describe?
5. A person walks up the stairs.
3rd Law!!!

20. 6. What is the net force and direction of movement?

21. 6. What is the net force and direction of movement?
1 Newton to the right

22. 7. Balanced or Unbalanced???

23. 7. Balanced or Unbalanced???

24. 8. The figure below shows two equal forces acting on a box
8. The figure below shows two equal forces acting on a box. The box is seen from above. In which direction will the box move?

25. 8. The figure below shows two equal forces acting on a box
8. The figure below shows two equal forces acting on a box. The box is seen from above. In which direction will the box move?
Southwest

26. 9. Which graph to the right shows an object that is NOT MOVING?
SLOPE

27. 9. Which graph to the right shows an object that is NOT MOVING?
Graph C
SLOPE

28. 10. Which graph to the right shows an object that is moving at a CONSTANT SPEED?
SLOPE

29. 10. Which graph to the right shows an object that is moving at a CONSTANT SPEED?
Graph B
SLOPE

30. 11. Which of the graphs to the right shows an object that is SPEEDING UP?
SLOPE

31. 11. Which of the graphs to the right shows an object that is SPEEDING UP?
Graph B
SLOPE

32. 12. Which of the graphs to the right shows an object that is moving at a CONSTANT SPEED?
SLOPE

33. 12. Which of the graphs to the right shows an object that is moving at a CONSTANT SPEED?
Graph D
SLOPE

34. 13. Which of the graphs to the right shows an object that is SLOWING DOWN?
SLOPE

35. 13. Which of the graphs to the right shows an object that is SLOWING DOWN?
Graph C
SLOPE

36. 14. Which of the graphs to the right shows an object that is SPEEDING UP and SLOWING DOWN back and forth?
SLOPE

37. 14. Which of the graphs to the right shows an object that is SPEEDING UP and SLOWING DOWN back and forth?
Graph A
SLOPE

38. 15. Name ALL the graphs to the right shows an object that is accelerating?
SLOPE

39. 15. Name ALL the graphs to the right shows an object that is accelerating?
Graphs A, B, and C.
SLOPE

40. 16. The graph to the right shows the motion of a cat over time
16. The graph to the right shows the motion of a cat over time. What was the cats average speed?
AVERAGE SLOPE

41. 16. The graph to the right shows the motion of a cat over time
16. The graph to the right shows the motion of a cat over time. What was the cats average speed?
0.8 m/s
AVERAGE SLOPE

42. 17. The graph to the right shows the motion of a cat over time
17. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was moving the FASTEST?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

43. 17. The graph to the right shows the motion of a cat over time
17. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was moving the FASTEST?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

44. 18. The graph to the right shows the motion of a cat over time
18. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was STATIONARY?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

45. 18. The graph to the right shows the motion of a cat over time
18. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was STATIONARY?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

46. 19. The graph to the right shows the motion of a cat over time
19. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was moving the SLOWEST?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

47. 19. The graph to the right shows the motion of a cat over time
19. The graph to the right shows the motion of a cat over time. During which interval does it show the cat was moving the SLOWEST?
Between 0 and 40 seconds.
Between 40 and 60 seconds.
Between 60 and 100 seconds.
SLOPE

48. 20. The graph to the right shows the motion of a cat over time
20. The graph to the right shows the motion of a cat over time. What is the cat’s average speed for the first 40 seconds of the trip?
SLOPE

49. 20. The graph to the right shows the motion of a cat over time
20. The graph to the right shows the motion of a cat over time. What is the cat’s average speed for the first 40 seconds of the trip?
0.5 m/s
SLOPE

50. 21. What is the acceleration of the above box?
45 Newtons of force
10 kilograms
21. What is the acceleration of the above box?
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS

51. 21. What is the acceleration of the above box?
45 Newtons of force
10 kilograms
21. What is the acceleration of the above box?
4.5 m/s2
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS

52. 22. A 12x12 moving box was loaded into a moving truck
22. A 12x12 moving box was loaded into a moving truck. If it took 800 joules to get the box 5 meters to the truck, how much force was applied to the box?
WORK = FORCE * DISTANCE
SI Unit: JOULE

53. 22. A 12x12 moving box was loaded into a moving truck
22. A 12x12 moving box was loaded into a moving truck. If it took 800 joules to get the box 5 meters to the truck, how much force was applied to the box?
F = 160 Newtons
WORK = FORCE * DISTANCE
SI Unit: JOULE

54. 23. A 12 kg ball was kicked and hit another student
23. A 12 kg ball was kicked and hit another student. The ball accelerated at 4 m/s2. How much force did the student take on impact?
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS

55. 23. A 12 kg ball was kicked and hit another student
23. A 12 kg ball was kicked and hit another student. The ball accelerated at 4 m/s2. How much force did the student take on impact?
F = 48 Newtons
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS

56. 24. A student lifted a book weighing 120 Newtons off the ground 1
24. A student lifted a book weighing 120 Newtons off the ground 1.5 meters. How much work did the student do?
WORK = FORCE * DISTANCE
SI Unit: JOULE

57. 24. A student lifted a book weighing 120 Newtons off the ground 1
24. A student lifted a book weighing 120 Newtons off the ground 1.5 meters. How much work did the student do?
W = 180 joules
WORK = FORCE * DISTANCE
SI Unit: JOULE

58. 25. A roller coaster is pulled up the first hill with a force of 225 N
25. A roller coaster is pulled up the first hill with a force of 225 N. It uses 18,000 joules of energy to get the roller coaster up the hill. How tall must the first hill of the roller coaster be?
WORK = FORCE * DISTANCE
SI Unit: JOULE

59. 25. A roller coaster is pulled up the first hill with a force of 225 N
25. A roller coaster is pulled up the first hill with a force of 225 N. It uses 18,000 joules of energy to get the roller coaster up the hill. How tall must the first hill of the roller coaster be?
d = 80 meters
WORK = FORCE * DISTANCE
SI Unit: JOULE

60. 26. Tommy hit a golf ball with a force of 1125 Newtons and it gave the ball an acceleration of 45 m/s2. What is the mass of the golf ball?
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS

61. 26. Tommy hit a golf ball with a force of 1125 Newtons and it gave the ball an acceleration of 45 m/s2. What is the mass of the golf ball?
m = 25 grams
FORCE = MASS * ACCELERATION
SI Unit: NEWTONS