Presentation is loading. Please wait.

Presentation is loading. Please wait.

Physics Beyond 2000 Chapter 1 Kinematics Physical Quantities Fundamental quantities Derived quantities.

Similar presentations


Presentation on theme: "Physics Beyond 2000 Chapter 1 Kinematics Physical Quantities Fundamental quantities Derived quantities."— Presentation transcript:

1

2 Physics Beyond 2000 Chapter 1 Kinematics

3 Physical Quantities Fundamental quantities Derived quantities

4 Fundamental Quantities QuantitySymbolSI Unit Massmkg Lengthlm Timets Others--

5 Derived Quantities Can be expressed in terms of the basic quantities Examples –Velocity –Example 1 –Any suggestions?

6 Derived Quantities More examples

7 Standard Prefixes Use prefixes for large and small numbers Table 1-3 Commonly used prefixes – giga, mega, kilo – centi, milli, micro, nana, pico

8 Significant Figures The leftmost non-zero digit is the most significant figure. If there is no decimal point, the rightmost non-zero digit will be the least significant figure. If there is a decimal point, the rightmost digit is always the least significant figure. The number of digits between the Most significant figure and least significant figure inclusive.

9 Scientific Notation Can indicate the number of significant numbers

10 Significant Figures Examples 5 and 6. See if you understand them.

11 Significant Figures Multiplication or division. –The least number of significant figures. Addition or subtraction. –The smallest number of significant digits on the right side of the decimal point.

12 Order of Magnitude Table 1-4.

13 Measurement Length –Meter rule –Vernier caliper –Micrometer screw gauge Practice

14 Measurement Time interval –Stop watch –Ticker tape timer –Timer scaler

15 Measurement Mass –Triple beam balance –Electronic balance

16 Measurement Computer data logging

17 Error Treatment Personal errors –Personal bias Random errors –Poor sensitivity of the apparatus System errors –Measuring instruments –Techniques

18 Accuracy and Precision Accuracy –How close the measurement to the true value Precision –Agreement among repeated measurements – Largest probable error tells the precision of the measurement

19 Accuracy and Precision Examples 9 and 10

20 Accuracy and Precision Sum and difference –The largest probable error is the sum of the probable errors of all the quantities. –Example 11

21 Accuracy and Precision Product, quotient and power –Derivatives needed

22 Kinematics Distance d Displacement s

23 Average Velocity Average velocity = displacement time taken

24 Instantaneous Velocity Rate of change of displacement in a very short time interval.

25 Uniform Velocity Average velocity = Instantaneous velocity when the velocity is uniform.

26 Speed Average speed Instantaneous speed

27 Speed and Velocity Example 13

28 Relative Velocity The velocity of A relative to B The velocity of B relative to A

29 Relative Velocity Example 14

30 Acceleration Average acceleration Instantaneous acceleration

31 Average acceleration Average acceleration = change in velocity time Example 15

32 Instantaneous acceleration Example 16

33 Velocity-time graph v-t graph v t Slope: = acceleration

34 v-t graph Uniform velocity: slope = 0 v t

35 v-t graph Uniform acceleration: slope = constant v t

36 Falling in viscous liquid Acceleration Uniform velocity

37 Falling in viscous liquid v t acceleration: slope=g at t=0 uniform speed: slope = 0

38 Bouncing ball with energy loss Falling: with uniform acceleration a = -g. Let upward vector quantities be positive.

39 v-t graph of a bouncing ball Uniform acceleration: slope = -g v t falling

40 Bouncing ball with energy loss Rebound: with large acceleration a. Let upward vector quantities be positive.

41 v-t graph of a bouncing ball Large acceleration on rebound v t falling rebound

42 Bouncing ball with energy loss Rising: with uniform acceleration a = -g. Let upward vector quantities be positive.

43 v-t graph of a bouncing ball Uniform acceleration: slope = -g v t falling rebound rising

44 v-t graph of a bouncing ball falling and rising have the same acceleration: slope = -g v t falling rebound rising The speed is less after rebound

45 Linear Motion: Motion along a straight line Uniformly accelerated motion: a = constant velocity time v u t0

46 Uniformly accelerated motion u = initial velocity (velocity at time = 0). v = final velocity (velocity at time = t). a = acceleration v = u + at

47 Uniformly accelerated motion = average velocity time v u t0 velocity

48 Uniformly accelerated motion time v u t0 velocity s = displacement = s = area below the graph

49 Equations of uniformly accelerated motion

50 Uniformly accelerated motion Example 17

51 Free falling: uniformly accelerated motion Let downward vector quantities be negative a = -g

52 Free falling: uniformly accelerated motion a = -g

53 Free falling: uniformly accelerated motion Example 18

54 Parabolic Motion Two dimensional motion under constant acceleration. There is acceleration perpendicular to the initial velocity Examples: –Projectile motion under gravity. –Electron moves into a uniform electric field.

55 Monkey and Hunter Experiment gun bullet aluminium foil electromagne t iron ball

56 Monkey and Hunter Experiment gun bullet aluminium foil electromagne t iron ball The bullet breaks the aluminium foil.

57 Monkey and Hunter Experiment gun bullet electromagne t iron ball Bullet moves under gravity. Iron ball begins to drop.

58 Monkey and Hunter Experiment gun bullet electromagne t Bullet is moving under gravity. Iron ball is dropping under gravity.

59 Monkey and Hunter Experiment gun electromagne t

60 Monkey and Hunter Experiment gun electromagne t The bullet hits the ball!

61 Monkey and Hunter Experiment The vertical motions of both the bullet and the iron are the same. The vertical motion of the bullet is independent of its horizontal motion.

62 Projectile trajectory y x

63 y x

64 y x u u = initial velocity = initial angle of inclination

65 Projectile trajectory y x u v = velocity at time t = angle of velocity to the horizontal at time t v Horizontal line

66 Projectile trajectory y x u = x-component of u = y-component of u

67 Projectile trajectory y x u

68 Projectile trajectory: accelerations y x u

69 Projectile trajectory y x u v Horizontal line vertical line = x-component of v = y-component of v

70 Projectile trajectory: velocity in horizontal direction y x u v Horizontal line

71 Projectile trajectory: velocity in vertical direction y x u v vertical line Horizontal line

72 Projectile trajectory: displacement y x x = x-component of s y = y-component of s s s = displacement

73 Projectile trajectory: horizontal displacement y x s s = displacement

74 Projectile trajectory: vertical displacement y x s s = displacement

75 Equation of trajectory: a parabolic path y x s s = displacement

76 Projectile trajectory: direction of motion y x u v Horizontal line vertical line Angle represents the direction of motion at time t.

77 Projectile trajectory: direction of motion y x u v Horizontal line vertical line

78 Projectile trajectory Example 19

79 Projectile trajectory: maximum height H y x u H At H, = 0

80 Projectile trajectory: range R y x u At R, y = 0 R

81 Projectile trajectory: maximum range R max y x u R max is maximum when

82 Projectile trajectory: maximum range R max y x u R max R is maximum when

83 Projectile trajectory: maximum range R max y x u R max

84 Projectile trajectory: time of flight t o y x u At time= t o, y = 0 R toto

85 Projectile trajectory: two angles for one range y x 1 R 2 u u 1 = - 2


Download ppt "Physics Beyond 2000 Chapter 1 Kinematics Physical Quantities Fundamental quantities Derived quantities."

Similar presentations


Ads by Google