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Horizontal plane
Inclined plane
Name __________________ Newtons LawsGo to
http://phet.colorado.edu/simulations/sims.php?sim=The_Rampand click
on Run Now.
Introduction:When an o !ect is dra""ed across a horizontal
sur#ace$ the #orce o# #riction that must e o%ercomedepends on the
normal #orce as n f F F = and the normal #orce is "i%en & W F n
= . When the sur#ace
ecomes an inclined plane$ the normal #orce chan"es and 'hen the
normal #orce chan"es$ so does the#riction. In this la $ &ou
'ill chan"e the an"le o# an inclined plane and o ser%e ho' 'ei"ht
is resol%edinto its components () n and ) //* usin" the asic tri"
#unctions.
Procedure: Play with the Sims Motion The Ramp +e sure to
sta& in the part o# the simulation. More features 'ill e used
later 'hen 'e
in%esti"ate ener"&. ,tart & pla&in" 'ith the ca inet
some. Ha%e #un$ reall&- No'- ack to 'ork. o%e the ca inet up
and do'n the ramp & dra""in" it 'ith &our mouse. o%e the
ramp to an an"le o# zero (horizontal* and dra' a #ree od&
dia"ram o# the ca inet here:
. 0n a horizontal plane$ the normal #orce is __e1ual_ to the
'ei"ht.2. The ca inet has a mass o# 33k". It there#ore has a normal
#orce o# __453N__ N and a #riction #orce
(on the horizontal plane* o# __246 N__ = 0.30 the ramp and dra'
a #ree od& dia"ram o# the ca inet in the o7 here:
8. The #orce do'n the plane and normal #orce are components o#
__Wei"ht__.6. +e#ore 'e add an applied #orce on the ramp$ there is
a #orce o# ___)riction_ that acts a"ainst the #orce
do'n the plane( )orce parallel*.
http://phet.colorado.edu/simulations/sims.php?sim=The_Ramphttp://phet.colorado.edu/simulations/sims.php?sim=The_Ramp
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9. When 'e appl& a #orce to "et the ca inet mo%in"$ the
#riction #orce acts in the __0pposite___ direction as mo%ement o#
the ca inet.
. Slowly increase an"le (3. de"rees at a time* o# the ramp until
the ca inet starts to mo%e on its o'n.What an"le is this? ___
.5____ = ;
sin" the #ormula #or #riction a o%e$ the #orce o# #riction is
_____25 ____ N.
2. I# the plane ca inet 'ere #rictionless$ 'hat an"le 'ould e
re1uired #or the ca inet to mo%e? __3.de"ree__
8. Wh&? __+ecause no #riction e7ist and a small #orce
produces due to such small inclination 'ill esu##icient to mo%e the
od&.__
@alculate #irst$ then test each o !ect in the ta le elo' 'ith
the simulation on a horizontal plane.
0 !ect ass Wei"ht Normal )orce $ @oe# o# )riction )riction )orce
to 0%ercomeAo" 9 k" 6< N 6< N 3. 3 6.
