Physics 102/chapter 8/rotational Motion

Front 1

ROTATIONAL SPEED (R.S.)

Back 1

-ANGULAR SPEED

-NUMBER OF ROTATIONS/REVOLUTIONS PER UNIT OF TIME. (RPM)

Front 2

TANGENTIAL SPEED (T.S.)

Back 2

-LINEAR SPEED OF SOMETHING MOVING ALONG A CIRCULAR PATH.

-DIRECTIONAL SPEED IS TANGENT TO CIRCUMFERENCE OF CIRCLE. (M/S OR KM/H)

-OUTSIDE EDGE/GREATER DISTANCE/GREATER SPEED

-CLOSE TO AXIS/SMALLER DISTANCE/SLOWER SPEED

Front 3

R.S./T.S. RELATIONSHIP

Back 3

-DIRECTLY PROPORTIONAL TO EACH OTHER AT ANY FIXED POINT FROM AXIS OF ROTATION.

-GREATER RPMS MORE M/S

Front 4

TANGENTIAL SPEED FORMULA

Back 4

RADIAL DISTANCE (r)
x ROTATIONAL SPEED (Ω)
~ TANGENTIAL SPEED (v)

(v ~ r x Ω)

Front 5

TANGENTIAL ACCELERATION

Back 5

-WHEN TANGENTIAL SPEED UNDERGOES CHANGE

-ANY CHANGE IN SPEED INDICATES CHANGE IN DIRECTION OF MOTION

Front 6

ROTATIONAL INERTIA

Back 6

-AN OBJECT ROTATING ON AN AXIS TENDS TO REMAIN ROTATING ABOUT SAME AXIS UNLESS INTERFERED WITH BY AN EXTERNAL INFLUENCE.

-DEPENDS ON MASS
(BIGGER MASS HARDER TO STOP SPINNING)

-DEPENDS ON DISTRIBUTION OF MASS ALONG AXIS OF ROTATION
(GREATER DISTANCE BETWEEN MASS CONCENTRATION AND AXIS, GREATER ROTATIONAL INERTIA)

Front 7

INERTIA FORMULA
SIMPLE PENDULUM

Back 7

I = mr²

Front 8

INERTIA FORMULA
HOOP NORMAL AXIS

Back 8

I = mr²

Front 9

INERTIA FORMULA
HOOP DIAMETER

Back 9

I = ½mr²

Front 10

INERTIA FORMULA
STICK ABOUT END

Back 10

I = ⅓mL

Front 11

INERTIA FORMULA
STICK ABOUT CENTER OF GRAVITY

Back 11

I = 1/12 mL²

Front 12

INERTIA FORMULA
SOLID CYLINDER

Back 12

I = ½mr²

Front 13

INERTIA FORMULA
SOLID SPHERE ABOUT CENTER OF GRAVITY

Back 13

I = 2/5 mr²

Front 14

TORQUE

Back 14

-ROTATIONAL COUNTERPART OF FORCE

-TWISTS OR CHANGES THE STATE OF ROTATION

-MAKES A STATIONARY OBJECT ROTATE

Front 15

TORQUE

Back 15

TORQUE = LEVER ARM X FORCE

Front 16

CENTER OF MASS (CM)

Back 16

AVG POSITION OF ALL MASS THAT MAKES UP THE OBJECT.

Front 17

CENTER OF GRAVITY (CG)

Back 17

AVG POSITION OF WEIGHT DISTRIBUTION (SAME AS CM)

Front 18

CM OF TRIANGLE

Back 18

CM = H/3 (H IS HEIGHT)

Front 19

CM OF CONE

Back 19

CM = H/4 (H IS THE HEIGHT)

Front 20

STABILITY

Back 20

-LINE STRAIGHT DOWN FROM CENTER OF GRAVITY OF OBJECT.
-IF LINE FALLS INSIDE BASE IT WILL BALANCE
-FALLS OUTSIDE BASE, IT WILL FALL

Front 21

EQUILIBRIUM

Back 21

CENTER OF GRAVITY FALLS WITHIN BASE

Front 22

CENTRIPETAL FORCE (CP.F.)

Back 22

-FORCE TOWARD A FIXED CENTER

-DEPENDS ON:

MASS(m)
TANGENTIAL SPEED (v)
RADIUS OF CURVATURE (r)

Front 23

CENTRIPETAL FORCE FORMULA

Back 23

CP.F. = mv² ÷ r

Front 24

CENTRIFUGAL FORCE (CF.F.)

Back 24

-FORCE AWAY FROM FIXED CENTER

Front 25

LOCATING CENTER OF GRAVITY
OF UNIFORM OBJECT

Back 25

MIDPOINT

Front 26

LOCATING CENTER OF GRAVITY
OF FREELY SUSPENDED OBJECT

Back 26

DIRECTLY BENEATH OR AT POINT OF SUSPENSION

Front 27

LOCATING CENTER OF GRAVITY
OF HOLLOW OBJECT

Back 27

GEOMETRICAL CENTER
(EVEN THOUGH NO MASS EXISTS)

Front 28

CENTRIFUGAL FORCE
ROTATING FRAME

Back 28

-FEELS LIKE GRAVITY, BUT NOT GRAVITY

-NOTHING PRODUCES IT, IT IS RESULT OF ROTATION

Front 29

SIMULATED GRAVITY

Back 29

-CAUSED BY BY CENTRIFUGAL FORCE

-STRUCTURES OF SMALL DIAMETER WILL HAVE TO SPIN MORE RAPIDLY

Front 30

LINEAR MOMENTUM

Back 30

-INERTIA OF MOTION

-MOMENTUM (mv)

Front 31

ANGULAR MOMENTUM

Back 31

-INERTIA OF ROTATION

-VECTOR QUANTITY

-DIRECTION + MAGNITUDE

Front 32

ANGULAR MOMENTUM FORMULA

Back 32

ROTATIONAL INERTIA
x
ROTATIONAL VELOCITY

Front 33

ANGULAR MOMENTUM FORMULA
OF SMALL RADIAL DISTANCE COMPARED TO AXIS OF ROTATION

Back 33

-EX. PLANET ORBITING SUN

-ANGULAR p =
MAGNITUDE OF LINEAR p (mv)
x RADIAL DISTANCE (r)

ANGULAR p = mvr

Front 34

ROTATIONAL VERSION OF NEWTONS FIRST LAW

Back 34

-AN OBJECT OR SYSTEM OF OBJECTS WILL MAINTAIN ITS ANGULAR p UNLESS ACTED UPON BY AN EXTERNAL NET TORQUE

Front 35

CONSERVATION OF ANGULAR MOMENTUM

DEFINITION

Back 35

-IF NO NET TORQUE ACTS ON A ROTATING SYSTEM, THE ANGULAR MOMENTUM OF THAT SYSTEM REMAINS CONSTANT.

-WITH NO EXTERNAL TORQUE, THE PRODUCT OF ROTATIONAL INERTIA AND ROTATIONAL VELOCITY AT ONE TIME WILL BE THE SAME AS AT ANY OTHER TIME

Front 36

CONSERVATION OF ANGULAR MOMENTUM

SIZE VS. SPEED

Back 36

-WHENEVER A ROTATING BODY CONTRACTS, ITS ROTATIONAL SPEED INCREASES

-WHENEVER A ROTATING BODY
EXPANDS ITS ROTATIONAL SPEED DECREASES

Front 37

EXAMPLE OF CONSERVATION OF
ANGULAR MOMENTUM

Back 37

-MAN LOW FRICTION TURNTABLE

-HOLDS ARMS AND WEIGHT OUT, SPINS SLOWLY

-BRINGS WEIGHTS IN, SPINS FAST

-Iw = iW

Front 38

LEVER ARM FORCE

Back 38

-DISTANCE WHICH PROVIDES LEVERAGE FOR TORQUE

-SHORTEST DISTANCE BETWEEN APPLIED FORCE AND ROTATATIONAL AXIS

-FORCE IS PERPINDICULAR TO LEVER ARM FORCE