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Allow Sad, But Do not Despair
Allow Sad, But Do not Despair
Allow Sad, But Do not Despair
Indicator Identify the amount of frequency, angular
frequency, period, and the travel angle contained in a circular motion with constant speed
Applying the principle of the wheels which are interconnected in a qualitative
Analyzing the amount of conduction-related linear motion and circular motion on a rolling motion with constant speed
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Circular motion is the motion of objects on the circular trajectory, speed of object speed and direction remain changeable.
Circular motion can be divided into:Uniform circular motion (GMB)Circular motion uniformly accelerated (GMBB)
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Uniform Circular MotionObjects moving in a circle is said irregular if the object is moving with constant angular velocity on a circular trajectoryThe position angle can be calculated by the equation: = ω. T, with t = time (s) Angular position versus time graph on the GMB:
t
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MAGNITUDES IN CIRCULAR MOTION
PERIOD (T):time needed by the body to take the path to a full circle. Where is the second unit (s).
T = 1/f FREQUENCY (f):Number of walks taken a full circle objects in one second. Where is the Hertz unit (Hz).
f = 1/T
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LINEAR VELOCITY (v):The distance traveled divided by the object latency
V = 2Лr / T
V = speed of the linear (m /s)r = radius of the circleT = period (second)
A
v
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ANGULAR VELOCITY (ω):The angles that have been taken within a certain time interval
ωω = = 2Л/T
With
ω = angular velocity (rad / s)T = period (s)
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Example Problem:
Bakri spur bike on a circular trajectory within 1 hour. In that time, Bakri has done 120 laps. Determine the period, frequency, kecepatn linear and angular velocity Bakri if the track has a diameter of 800 m!
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Unknown:a.d = 800 m r = 400 mb. t = 1 jam = 3600 sc. n = 120 lap
Asked: a. T = …?b. f = …?c. v = …?d. ω = …?
Answer:
x
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Centripetal Acceleration Centripetal acceleration is the
acceleration of the direction toward the center of the circle
Acceleration occurs because the linear
speed of the object that keeps changing.
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Centripetal acceleration is mathematically written
as = V2/rWith as = centripetal acceleration (m/s2) V = velocity (m / s) r = radius of circle (m)
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Example Problem:
Bambang riding a motorcycle through a bend circle 20 m fingered finger when going to school. If Bambang motor speed 10 m / s, determine the acceleration Bambang trajectory leading to the center!
Unknown :
Asked : as = .....?
Answer :as = v2/r =(10)2/20
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Position Angle The position angle () is the position of particle
moving along the arc of linear displacement (s) within r from the center of the circle.Mathematically calculated angular position:
= s / r Where the unit in radians
s in meters r in meters
Since the circumference of a circle = 2Пr then = 2П rad
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Regular Changed Circular Motion(GMBB)
Said to be irregular objects moving in a circle if the angle velocity uniformly accelerated so that a constant angular acceleration.
Graph velocity function of time at GMBB: ω Mathematically,
angular velocity ωo on GMBB : ωt = ωo + t t
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The position angle traveled by the moving body uniformly accelerated circular mathematically written:
Θ = ωo . t + ½. .t2
With Θ = angle position of the object (rad)ωo = initial angular velocity (rad/s) = angular acceleration (rad/s2)
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Relations Wheelsa. Concentric relationship: On the relationship of two concentric wheels direction of rotation and angular velocity both same wheel. So: ω1 = ω2b. relationships intersect In this connection both the direction of rotation linear speed of the two opposite and equal. So v1 = v2c. Relationship of two wheels with a rope, then the direction of rotation and linear speed of the same. So v1 = v2
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Look at pictures of the three wheels are in a relationship as follows:
If Rc = 4 cm, 6 cm and Rb = Ra = 8cm, and the wheel angular velocity w = 8 rad / s. discussion:1. a wheel angular velocity2. wheel linear speed of c
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Solution
Given:Ra = 4 cm = 4x10 -2 mRb = 6 cm = 6x10 -2 mRc = 8 cm = 8x10 -2 mωb = 8 rad / sasked:1. ωa2. vc
Answer:1. va = vb ωaRa = ωc.Rc ωa. (4x10 -2) = 8. (6x10 -2) ωa = 12 rad / s. 2. ωa = ωc vc = ωa.Rc vc = 12. (8x10 -2) vc = 0.96 m / s
Allow Sad, But Do not Despair
Allow Sad, But Do not Despair
ReferensiReferensi
1. Supriyanto.2006. Fisika SMA kelas X2. Marthin Kanginan. 2006. Fisika SMA kelas X3. Karyono.2007.Fisika SMA dan MA kelas XII4. Sutejo.2007.Fisika X
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Irna Ilfiana(09330105)
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