1. Mr. Chimenti Room 125 West Branch

2. Scalar and Vector Values Scalar any value that has magnitude but no direction Examples of scalar quantities Height, distance, mass, volume, density, etc. Vector Any value that has magnitude and direction Vectors are drawn as arrows in the direction of the magnitude The length of the arrow representing the vector is proportional to the magnitude of the vector Examples of vector values Velocity, acceleration, force, weight

3. Adding and subtracting vectors Vector addition Draw vectors and place them “tip to tail” The “resultant” vector is drawn from the tail of the first vector to the tail of the last vector Vector subtraction Subtraction is done by drawing a vector of the same size but opposite direction as the vector that is being subtracted Web Link

4. Vector addition Vector a Vector b a b a+b resultant a b a-b resultant

5. Multiplying and dividing vectors Vectors can also be multiplied or divided by scalar values making them larger or smaller a 2a

6. Dimensional analysis Conversion factor used to convert a measured quantity to a different unit of measure without changing the relative amount. To accomplish this, a ratio (fraction) is established that equals one (1). Conversion fraction=units you want/units you have=1

7. Practice Conversions 1. How many seconds are in 6 minutes? 360 seconds 2. How many centimeters are in 27 inches? 68.58 centimeters 3. If a truck weighs 15,356 pounds, how many tons is it? 7.678 tons 4. If you had 10.5 gallons of milk, how many pints would you have? 84 pints 5. Students go to school for 180 days. How many minutes is this equal to? 259,200 minutes

8. How many seconds are in 6 minutes? 6 minutes  seconds (6 minutes) 1 ( ) seconds minute 360 seconds 60 1 = (6)(60 seconds) (1)(1) = Step 1 – Read the question and determine what information it provides you with (starting point & final destination) Step 2 – Write down your starting point and your final destination 1 minute = 60 seconds Step 3 – Determine how you will get from your starting point to your final destination (list any “connections” or conversion factors) Step 4 – Create a fraction by placing your starting point over one Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is YES, so we move on to step 9 Step 9 – Cancel all diagonal units. Once this is done, your final destination should be the only unit left – in this case seconds Step 10 – Multiply the top of the fractions; multiply the bottom of the fractions; divide the product of the top by the product of the bottom Starting Point Final Destination

9. How many centimeters are in 27 inches? 27 inches  centimeters (27 inches) 1 ( ) cm inch 68.58 centimeters 2.54 1 = (27)(2.54 cm) (1)(1) = Step 1 – Read the question and determine what information it provides you with (starting point & final destination) Step 2 – Write down your starting point and your final destination 1 inch = 2.54 centimeters Step 3 – Determine how you will get from your starting point to your final destination (list any “connections” or conversion factors) Step 4 – Create a fraction by placing your starting point over one Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is YES, so we move on to step 9 Step 9 – Cancel all diagonal units. Once this is done, your final destination should be the only unit left – in this case centimeters Step 10 – Multiply the top of the fractions; multiply the bottom of the fractions; divide the product of the top by the product of the bottom Starting Point Final Destination

10. If a truck weighs 15,356 pounds, how many tons is it? 15,356 pounds  tons (15,356 lbs.) 1 ( ) ton lbs. 7.678 tons 1 2000 = (15,356)(1 ton) (1)(2000) = Step 1 – Read the question and determine what information it provides you with (starting point & final destination) Step 2 – Write down your starting point and your final destination 2000 pounds = 1 ton Step 3 – Determine how you will get from your starting point to your final destination (list any “connections” or conversion factors) Step 4 – Create a fraction by placing your starting point over one Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is YES, so we move on to step 9 Step 9 – Cancel all diagonal units. Once this is done, your final destination should be the only unit left – in this case tons Step 10 – Multiply the top of the fractions; multiply the bottom of the fractions; divide the product of the top by the product of the bottom Starting Point Final Destination

11. If you had 10.5 gallons of milk, how many pints would you have? 10.5 gallons  pints (10.5 gallons) 1 ( ) quarts gallon 84 pints 4 1 = (10.5)(4)(2 pints) (1)(1)(1) = Step 1 – Read the question and determine what information it provides you with (starting point & final destination) Step 2 – Write down your starting point and your final destination 1 gallon = 4 quarts 1 quart = 2 pints Step 3 – Determine how you will get from your starting point to your final destination (list any “connections” or conversion factors) Step 4 – Create a fraction by placing your starting point over one Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is NO, so we move back to step 5 Step 9 – Cancel all diagonal units. Once this is done, your final destination should be the only unit left – in this case pints Step 10 – Multiply the top of the fractions; multiply the bottom of the fractions; divide the product of the top by the product of the bottom Starting PointFinal Destination ( ) pints quart 2 1 Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is YES, so we move on to step 9

12. Students go to school for 180 days. How many minutes is this equal to? 180 days  minutes (180 days) 1 ( ) hours day 259,200 minutes 24 1 = (180)(24)(60 minutes) (1)(1)(1) = Step 1 – Read the question and determine what information it provides you with (starting point & final destination) Step 2 – Write down your starting point and your final destination 1 day = 24 hours 1 hour = 60 minutes Step 3 – Determine how you will get from your starting point to your final destination (list any “connections” or conversion factors) Step 4 – Create a fraction by placing your starting point over one Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is NO, so we move back to step 5 Step 9 – Cancel all diagonal units. Once this is done, your final destination should be the only unit left – in this case minutes Step 10 – Multiply the top of the fractions; multiply the bottom of the fractions; divide the product of the top by the product of the bottom Starting PointFinal Destination ( ) minutes hour 60 1 Step 5 – Multiply between fractions Step 6 – Write in the bottom unit of the new fraction (this is the same as the top unit of your previous fraction) Step 7 – Write the appropriate conversion factor into the fraction. Your bottom unit will guide you. Step 8 – Determine if this top unit is the desired unit (your final destination). In this case the answer is YES, so we move on to step 9

13. Online Tutorials http://www2.wwnorton.com/college/chemistry/gilbert/tutori als/ch1.htm http://www2.wwnorton.com/college/chemistry/gilbert/tutori als/ch1.htm (click on “view tutorial” for dimensional analysis) http://www.wfu.edu/~ylwong/chem/dimensionanalysis/practi ce/index.html http://www.wfu.edu/~ylwong/chem/dimensionanalysis/practi ce/index.html (click on examples under dimensional analysis on the left side of the page) http://chemistry.alanearhart.org/Tutorials/DimAnal/ Interactive Quiz http://chem.lapeer.org/Exams/DimAnalQuiz.html

14. The ladder method Used for metric units Metric units that have common base units can be converted by moving a decimal point to the left or right This method is called the ladder method

16. Describing and measuring motion Motion Anytime that the distance between 2 objects changes Motion is relative to a reference point (usually an object that is stationary) Distance Measurement of how far one point is from another SI unit=meter (a little more than 39 inches) An Olympic pool=50m, football field=91m

17. Calculating Speed (Scalar values) Speed The distance that an object travels within a period of time Speed=distance÷time Average speed The total distance traveled divided by the total time Speed changes throughout the trip Ave. speed=total distance÷ total time Instantaneous speed Rate of motion at a certain point in time

18. Velocity (vector value) Velocity A measure of the speed and direction of motion a vector value (magnitude and direction) Vectors are drawn as arrows

19. Practice problem #1 If it takes Ashley 5 seconds to run from the batters box to first base at an average speed (velocity) of 10 meters per second, what is the distance she covers in that time?

20. Practice problem Mike rides his motorcycle at an average speed (velocity) of 30 meters/second for 15 seconds, how far did he ride?

21. Practice problem Sarah backstrokes at an average speed of 20 meters per second, how long will it take her to complete the race of 200 meters length?

22. Your mom threw a pie pan across the room at you. If she threw it at 10m/s and the room is 15m across how long did you wait to be struck in the face?

23. Tony Stewart finish the Daytona 500 (500mi) in 4 hours what was his average speed?

24. How long does it take a baseball thrown at 20m/s to travel 100m?

25. Suppose Chuck Norris roundhouse kicks a boy named Dan in the head. How far would his severed head travel in 4s if the severed head was traveling at 100m/s?

26. Suppose a bullet travels at 100m/s out of a rifle. How long would it take for a sniper to shoot a terrorist 2000m away?

27. Mr. Chimenti is able to run at a rate of 10 yds per second. How long does it take him to run 40 yds?

28. Graphing motion Plotting distance (y-axis) over time (x-axis) is one way to display motion The slope of a distance vs. time graph gives you the instantaneous velocity

29. Lab safety videos

30. Bingo words Motion Reference point SI Meter Speed Average speed Instantaneous speed Velocity Slope Acceleration Time Distance Theory of plate tectonics m m/s s Vector Scalar Kilo- Centi- Milli- Khdudcm Slope S=d/t force

31. Acceleration (vector value) Acceleration-rate at which velocity changes 3 ways: speed up, slow down or change direction Acceleration always occurs in the direction of a force applied to an object Acceleration=(final velocity-initial velocity)÷time The slope of a velocity (y) vs. time (x) graph will give you the acceleration of an object A curved line on a distance vs. time graph tells you that acceleration is occurring

32. Acceleration (vector value)

33. Acceleration quiz 1. A soccer ball was kicked by Mr. Learish. It’s velocity reached 10m/s after being in contact with the teachers foot for 1.5s. What was his acceleration? 2. A student had a football thrown at him at a speed of 25m/s. It took 2 seconds to come to a stop. What was its acceleration. 3. Your mom fell off the roof after retrieving a football that you threw up there. She fell for a total of 4s. Her velocity that she reached was 39.6m/s before she struck the ground. What was her acceleration?

34. Forces (vector value) Force-any push or pull on an object F=ma Measured in Newtons (N) 1N=1kgm/s 2 2 or more forces can be added together forming a “net force”

35. Forces (continued) Unbalanced forces Combination of forces which cause an object to accelerate One or more forces overpower the other force or forces Balanced forces Combination of forces which do not cause an object to accelerate

36. Friction Friction-forces exerted by 2 objects on one another when they rub against one another Frictional forces always oppose motion Frictional force converts motion (kinetic energy) of an object into thermal energy (heat)

37. 4 types of friction Static friction Force opposing the motion of an object that is not in motion Sliding friction Force opposing the motion of an object that is sliding over the surface of another Rolling friction Force opposing the motion of an object that is rolling over top of another Fluid friction Force opposing the motion of an object and the fluid that it is moving through

38. Gravity Gravity-force of attraction which pulls objects toward one another All objects in the universe are attracted to one another Larger objects pull harder than small one (increase mass, increase gravity) The closer two objects are the greater the gravity is between them (decrease distance, increase gravity) Mass=the amount of matter in an object Weight=the magnitude of the force of gravity on an object (increase mass, increase weight) Mass is commonly calculated by measuring the force of gravity acting on an object

39. Newton’s laws of motion 1 st law of motion An object at rest will stay at rest, an object in motion will stay in motion unless acted on by an unbalanced force. Aka the “law of inertia” Inertia=tendency of an object in motion to resist a change in its motion The greater the mass of an object the more inertia it possesses

40. Newton’s laws of motion 2 nd law of motion An object will accelerate in the direction of an unbalanced force Acceleration=net force÷mass

41. Newtons laws of motion 3 rd law of motion If one object exerts a force on another object the other object exerts a force of equal size in the opposite direction on the first object Aka “action-reaction” Action-reaction forces do not always cancel out each others motion due to differences in mass

42. Gravity and Motion Free-fall=condition in which the only force on an object is gravity Acceleration due to gravity is 9.8m/s 2 Free fall occurs in the absence of air resistance All objects free fall at the same rate Air resistance Def.=Fluid friction between an object and air A reason why some objects fall slower than others Terminal velocity The greatest velocity that an object in free fall can reach (air resistance=objects weight)

43. Projectile motion Describes the motion of any object which is thrown Projectile motion occurs in 2 or 3 dimensions

44. Circular motion Objects travel in a circular path due to centripetal force (“center seeking” force) Satellite Any object that is in orbit around another object Satellites in orbit around Earth continuously fall toward but their forward motion allows them to travel in a circle around it

45. momentum A characteristic of all moving objects Describes how difficult it is to stop an objects motion Momentum=mass x velocity Law of conservation of momentum The sum of the momentum of objects in a collision do not change

46. Types of Collisions Elastic Collision in which two objects bounce off of each other Both objects remain in their original shapes No energy is lost Inelastic When two objects collide and move together as if they were one mass after the collision Some kinetic energy is lost as sound energy and internal energy when one or both objects changes shape, some energy is also lost as heat rugby A special surprise football hockey

47. Perfectly inelastic collisions In a collision that is inelastic the following formula can be used to describe the momentum of the objects before and after the collision m 1 v 1,i +m 2 v 2,i =(m 1 +m 2 )v f

48. Elastic collisions If a collision is perfectly inelastic then all of the kinetic energy is conserved (not converted into different forms) However, this rarely occurs These formulas describe elastic collisions: m 1 v 1,i +m 2 v 2,i =m 1 v 1,f +m 2 v 2,f

49. Relay race A car accelerates from 0m/s to 25m/s in 2s. What is its acceleration?

50. Relay Race An object with 220kg of mass accelerates at a rate of 4m/s 2. what force is being applied to it?

51. Relay Race If an objects momentum is 100kgm/s and it is moving at 2.5m/s what is its mass?

52. Relay Race A snail departs from the 10cm mark on a meter stick at 2:00. He arrives at the 75cm mark at 2:25. What was his average speed?

53. Relay Race Hines Ward caught a football traveling at 10m/s? Ray Lewis hit him in the head stopping his motion in.4s? What was Hines acceleration?

54. Relay Race Lets assume Hines weighs 98kg. Since his acceleration was 25m/s 2. What force did Ray apply to his head?

55. Relay Race The door to the restroom accelerates at a rate of 25m/s2 when Beans runs into it in a rush to go #1. If he applied 500N of force to the door, what is the doors mass?

56. Relay Race A bullet travels at a rate of 1000m/s. If it has a momentum of 33kgm/s what is its mass?

57. Newtons Toy box Place the wooden ball on the table. Push the ball gently with your hand. 1. Draw what happens to the ball

58. Newtons toy box Start the ball rolling away from you Then give the ball a gentle push with your right hand 2. draw and describe what happens the direction of the ball’s motion.

59. Newtons toy box 3. When you push the ball, you are exerting a force on it. Was the direction of the force toward the left or the right? Which way did the ball move after you pushed it? 4. In formal terms, Newton’s first law of motion states: “An object will remain at rest or in uniform motion unless acted on by an unbalanced external force.” Describe how you demonstrated Newton’s first law of motion.

60. Newton’s Toy box 5. Hold the wooden ball in your hand. Release the ball. What happens to the ball? What force is making the ball move? What is the direction of this force? 6. Hold the wooden ball in your hand again. What force is keeping the ball from falling? What is the direction of this force?

61. Newton’s toy box 7. You can measure the strength of the forces acting on the ball by using a spring scale. First put the ball in the mesh bag. Then hang the bag from the spring scale. The spring scale measures the upward force needed to keep the ball from falling. The strength of this force can be described in a unit called the newton (N). What is the strength in newton of the force supporting the ball?

62. Newton’s Toy box 8. When the spring scale or your hand supports the ball, you apply just enough force to keep the ball from falling. The force you apply is the same strength as the downward gravity force. Therefore what is the strength of the gravity force on the ball? 9. The strength of gravity force is also called weight. What is the weight of the ball?

63. Newton’s Toy box 10. Gravity force can also be expressed in pounds. Approximately what is the strength in pounds of the gravity force pulling on you? To convert your weight in pounds to newtons, multiply by 4.448. What is your weight in newtons? How strong is the upward force exerted by your chair as you sit in it?

64. Ch. 4 and 5

65. Work Product of a force exerted over a distance Formula: W=Fd (w=work, F=force, d=displacement) Work is expressed in Nm or J (joules) Work done by anything is found using the formula for net work W net =Fd

66. Energy The ability to bring about a change Measured in joules (kgm 2 /s 2 )

67. Potential energy Stored energy Gravitational Energy due to an objects position above Earths surface Elastic Energy due to an object being stretched or bent Chemical Energy stored due to the presence of chemical bonds

68. Kinetic energy The energy of motion Can be organized movement ex. A rolling ball, a flying squirrel, ice skater, etc. Can be unorganized movement of molecules Higher temperature=more kinetic energy

69. Conservation of energy Law of conservation of energy in a closed system energy can not be created or destroyed It can be converted into different forms

70. Mechanical energy The sum of the kinetic energy and all of the potential energy of an object ME=KE+ΣPE Due to the law of conservation of energy we can derive the following formula ME i =ME f

71. Power The rate at which work is done (energy is transformed) P=W/∆t (P=power, W=work, t=time) P=Fv (P=power, F=force, V=velocity) The metric unit for power is the watt (W)

72. Torque and simple machines Torque is a measure of a forces ability to rotate and object The torque on an object depends on the magnitude of the applied force and the length of the lever arm Simple machines provide a mechanical advantage by trading distance for force

73. 73 Simple Machines The six simple machines are: Lever Wheel and Axle Pulley Inclined Plane Wedge Screw

74. 74 Simple Machines A machine is a device that helps make work easier to perform by accomplishing one or more of the following functions: transferring a force from one place to another, changing the direction of a force, increasing the magnitude of a force, or increasing the distance or speed of a force.

75. 75 Mechanical Advantage input force =the force you apply output force =force which is applied to the task When a machine takes a small input force and increases the magnitude of the output force, a mechanical advantage has been produced.

76. 76 Mechanical Advantage MA = output/input Mechanical advantage is the ratio of output force divided by input force. If the output force is bigger than the input force, a machine has a mechanical advantage greater than one. If a machine increases an input force of 10 pounds to an output force of 100 pounds, the machine has a mechanical advantage (MA) of 10. In machines that increase distance instead of force, the MA is the ratio of the output distance and input distance.

77. 77 The Lever A lever is a rigid bar that rotates around a fixed point called the fulcrum. The bar may be either straight or curved. In use, a lever has both an effort (or applied) force and a load (resistant force).

78. 78 The 3 Classes of Levers The class of a lever is determined by the location of the effort force and the load relative to the fulcrum.

79. 79 To find the MA of a lever, divide the output force by the input force, or divide the length of the resistance arm by the length of the effort arm.

80. 80 Wheel and Axle The wheel and axle is a simple machine consisting of a large wheel rigidly secured to a smaller wheel or shaft, called an axle. When either the wheel or axle turns, the other part also turns. One full revolution of either part causes one full revolution of the other part. Mechanical advantage of a wheel and axle=diameter of wheel/diameter of axle

81. 81 Pulley a grooved wheel that turns freely in a frame called a block. can change the direction of a force or to gain a mechanical advantage, depending on how the pulley is arranged. Fixed pulley=one that does not rise or fall with the load being moved. Changes direction No mechanical advantage moveable pulley =one that rises and falls with the load that is being moved. creates a mechanical advantage does not change the direction of a force. The mechanical advantage of a moveable pulley is equal to the number of ropes that support the moveable pulley.

82. What is the mechanical advantage of the moveable pulley systems? 82

83. What is the mechanical advantage of the moveable pulley systems? 83

84. 84 Inclined Plane An inclined plane is an even sloping surface. The inclined plane makes it easier to move a weight from a lower to higher elevation.

85. 85 Although it takes less force for car A to get to the top of the ramp, all the cars do the same amount of work. A B C

86. 86 Inclined Plane A wagon trail on a steep hill will often traverse back and forth to reduce the slope experienced by a team pulling a heavily loaded wagon. This same technique is used today in modern freeways which travel winding paths through steep mountain passes.

87. 87 Wedge The wedge is a modification of the inclined plane. Wedges are used as either separating or holding devices. A wedge can either be composed of one or two inclined planes. A double wedge can be thought of as two inclined planes joined together with their sloping surfaces outward.

88. 88 Screw The screw is also a modified version of the inclined plane. It is a ramp wrapped around a post