analisi materi fisika

7/31/2019 ANALISI MATERI FISIKA

1/16

PHYSICS DEPARTMENT

FACULTY OF MATHEMATIC & NATURAL SCIENCESTATE UNIVERSITY OF PADANG


2/16


3/16


4/16


5/16

A falling bodies is an object

which is falling under the soleinfluence of gravity.

The characteristics about a freefalling object: Free falling objects do not

encounter air resistance.

All free falling objects (onEarth) accelerate downwards ata rate of 9.8 m/s2

WHAT IS FALLING BODIES??


6/16


7/16

The remarkableobservation that all free

falling objects fall withthe same acceleration wasfirst proposed by GalileoGalilei nearly 400 yearsago.

Acceleration offalling objects is alwaysthe same, no matter howlight or heavy.

Acceleration dueto gravity, g = 9.8 m/s2

GALILLEO GALILLEI
http://images.google.com.ph/imgres?imgurl=http://www.biografiasyvidas.com/monografia/galileo/fotos/galileo_domenico_crespi.jpg&imgrefurl=http://www.biografiasyvidas.com/monografia/galileo/index.htm&h=275&w=340&sz=10&hl=tl&start=2&tbnid=XPlbMxrp9EzqbM:&tbnh=96&tbnw=119&prev=/images?q=Galileo&gbv=2&svnum=10&hl=tl


8/16

NEWTON & ARISTOTLENewtons Second

Law changed theunderstanding of theaffect of gravity on freefalling objects.

Free falling

objects are dropped sothat the only forceacting upon the object isgravity.

Aristotlebelieved that if 10 kg

object and a 1 kg objectwere dropped that the 10kg object would fall tentimes faster than the 1kg object because itweighed ten times as

much.


9/16

Newton explains Aristotles

theory that gravity pulls ten times asmuch on a 10 kg free falling object as a 1kg object and also Galileos observationsthat the fall at the same acceleration.


10/16

Heavier Objects fall faster than

light ones

Acceleration is the same velocity

SOME MISCONCEPTIONS

People commonly have themisconception that heavier objects fallfaster than lighter ones. They have thismisconception because that is what theycommonly observe. In the real world thereis air resistance. With air resistance thismisconception is true.

Students assuming that twoparticles with identical velocities (at aninstant) have identical accelerations(similarly), two particles with identicalpositions (at an instant) have identicalspeeds).
http://d/-DATA%20KULIAH-/SEMESTER%205/analisis/FANNI&DILLA_FREEFALL/Physics_%20Free-Falling%20Objects.mp4http://d/-DATA%20KULIAH-/SEMESTER%205/analisis/FANNI&DILLA_FREEFALL/Physics_%20Free-Falling%20Objects.mp4


11/16

Acceleration experienced by eachobject in free fall is always the same is equal

to gravity. It can be proved mathematicallyby the following equation :

vy = vyo + gtequation becomes:

vy = gt

Through this equation, it is knownthat the speed of falling bodies heavilyinfluenced by the acceleration of gravity (g)

and time (t). Since the g-value fixed (9.8m/s2), then the equation above, we see thatthe value of the speed of falling objects isdetermined by the time (t). Velocity is alwayschanging with time or in other words everyunit of time increases the velocity.


12/16

The Acceleration of Falling objects

Depends Upon its Mass

Freely Falling Bodies Can only MoveDownward

According to newton's law ofgravitation the speed of a falling object doesnot depend on the mass of an object. Allobjects fall with an acceleration ofgravitation 9.8m/s2.

In kinematic equations, replace theacceleration awith g=9.81m/s2. Use "+g" if theobject is moving downward while use "-g" if itis moving upward.


13/16


14/16

There is no Gravity in a Vacuum

Objects falling in a vacuum always fallat the same rate. newton law of gravity, it isstated that the force of gravity is inverselyproportional to the square of the distancebetween objects. So, in the space that far

though, there is the force of gravity.However, the magnitude of the

gravitational force is so small by the distancefrom the earth. In addition, the influence ofother celestial bodies such as stars, otherplanets, so that the resultant of the forcesacting on it is small. Thus, it can be concludedthat in space there is the force of gravity
http://d/-DATA%20KULIAH-/SEMESTER%205/analisis/FANNI&DILLA_FREEFALL/Free%20fall%20in%20a%20vacuum.mp4


15/16

Gravity Only Acts on Things when

They are FallingGravity not only acts on things when

they are falling, but gravity also applies tostationery objects and moving object. Forexample, block is placed on the floor the blockhas weight which affected by mass andgravity.

w = m.g


16/16

THE END

analisi materi fisika

Documents