Boardworks Ltd 20041 of 20 Boardworks Ltd 20051 of 24KS3
Physics7K Forces and their Effects Boardworks Ltd 20041 of 20
Boardworks Ltd 20052 of 247K Forces and their Effectsontents Fee!
the force Friction Forces in water "ei#ht and $ass S%$$ary
acti&ities Boardworks Ltd 20041 of 20 Boardworks Ltd 20053 of
24A force is a push or a pull.A force cannot be seen but you can
see how a force affects an object."hat is a force' Boardworks Ltd
20041 of 20 Boardworks Ltd 20054 of 24"hat ty(e of force'
Boardworks Ltd 20041 of 20 Boardworks Ltd 20055 of 2410 ) 10 )If
you link two newtonmeters and pull equally hard from both ends, the
forces recorded on both will be the same.*a!anced forces"hen forces
are *a!ancedThe forces acting on the central hooks cancel each
other out they are equal in magnitude and opposite in direction.
Because the forces are *a!anced the hooks do not $o&e.
Boardworks Ltd 20041 of 20 Boardworks Ltd 2005+ of 2411 ) 10 )hat
happens if the pull on one end is greater than the pull on the
other end!%n*a!anced forces$o&e$ent"hen forces are
%n*a!ancedThe forces acting on the hooks are no longer balanced.
Both hooks will start to mo"e to the left their s(eed wi!! chan#e.
This is called acce!eration.#nbalanced forces lead to a change in
speed or direction. Boardworks Ltd 20041 of 20 Boardworks Ltd 20057
of 24In which direction will these stationary objects mo"e!Ba!anced
or %n*a!anced forces' Boardworks Ltd 20041 of 20 Boardworks Ltd
2005, of 247K Forces and their Effectsontents Fee! the force
Friction Forces in water "ei#ht and $ass S%$$ary acti&ities
Boardworks Ltd 20041 of 20 Boardworks Ltd 2005- of 24If you rub
your hands together they get warm. There is resistance to the
rubbing motion.hat is the name of this resisti"e force called!hat
causes this force!$our hands might look smooth, but on a
microscopic le"el they ha"e rough surfaces. %o when you rub your
hands together you feel the resisti"e force of friction."hat is
friction'It is called friction. Boardworks Ltd 20041 of 20
Boardworks Ltd 200510 of 24Friction always tries to slow mo"ing
objects down.e say it o((oses $otion.There is a ma&imum "alue
for the frictional force which depends on'/ore a*o%t
friction(riction is created whene"er two touching objects or
surfaces mo"e past each other.(riction also occurs when things mo"e
through air.This is called air resistance or dra#. the force
pushing the two surfaces together) the state of the surfaces in
contact. Boardworks Ltd 20041 of 20 Boardworks Ltd 200511 of 24*ne
more!+robably the most important,-abel all sources of friction that
can act on this bike.tyre and road*rake (ad and ri$whee!
*earin#whee! *earin#(eda! *earin#!inks in chainair resistance or
.drag/"hat are the so%rces of friction' Boardworks Ltd 20041 of 20
Boardworks Ltd 200512 of 24Effects of frictiona! forces Boardworks
Ltd 20041 of 20 Boardworks Ltd 200513 of 247K Forces and their
Effectsontents Fee! the force Friction Forces in water "ei#ht and
$ass S%$$ary acti&ities Boardworks Ltd 20041 of 20 Boardworks
Ltd 200514 of 24%(thr%stfriction thr%stwei#hthat is thr%st! The
force that pushes an object forward. hat is %(thr%st! The force
that pushes an object upwards in a liquid or a gas, also called
buoyancy.Forces in water Boardworks Ltd 20041 of 20 Boardworks Ltd
200515 of 24%(thr%st or *%oyancythr%stair
resistancefrictionwei#ht-abel the forces acting on the ferry as it
sails to (rance.Ferry forces Boardworks Ltd 20041 of 20 Boardworks
Ltd 20051+ of 24hat happens to the weight of the ship!hat happens
to the upthrust on the ship!hich is the largest force 0 weight or
upthrust! increases*oth e0%a!increasesThe ferry arri"es at 1alais
and is loaded with tra"ellers.han#in# forces Boardworks Ltd 20041
of 20 Boardworks Ltd 200517 of 247K Forces and their Effectsontents
Fee! the force Friction Forces in water "ei#ht and $ass S%$$ary
acti&ities Boardworks Ltd 20041 of 20 Boardworks Ltd 20051, of
24/ass and wei#ht are not the sa$e1"hat are $ass and wei#ht'/ass is
the a$o%nt of $atter in an object and is measured in ki!o#ra$s.
2ass is not a force."ei#ht is a force and is caused by the pull of
gra"ity acting on a mass . -ike other forces, weight is measured in
newtons and has both magnitude and direction.2ass will ha"e the
same "alue anywhere in the #ni"erse, including space.eight has
different "alues depending on where you are in the #ni"erse.
Boardworks Ltd 20041 of 20 Boardworks Ltd 20051- of 24"ei#ht and
$ass on the /oonThe force of gra"ity is less on the 2oon than it is
on 3arth. This is because the 2oon has a smaller mass than the
3arth.4owe"er, the astronaut still has the same body and the same
mass' he just weighs less because gra"ity is weaker on the 2oon.Any
object will weigh less on the 2oon than it does on 3arth.An
astronaut could jump 56 feet into the air on the 2oon because
gra"ity is less. Boardworks Ltd 20041 of 20 Boardworks Ltd 200520
of 24A scientist should ne&er say'.She weighs 50 kilograms,/but
should always say'2a!kin# a*o%t wei#ht and $ass.She has a mass of
50 kilograms/. .Her weight is about 500 newtons/.Alternati"ely, the
scientist could say'.The gravitational force acting on her mass is
about 500 newtons/.This is the same as saying' Boardworks Ltd 20041
of 20 Boardworks Ltd 200521 of 247K Forces and their Effectsontents
Fee! the force Friction Forces in water "ei#ht and $ass S%$$ary
acti&ities Boardworks Ltd 20041 of 20 Boardworks Ltd 200522 of
243!ossaryair resistance 4 A frictional force that acts against an
object mo"ing through air.force 4 A push or a pull, measured in
newtons 789.friction 4 A force that occurs between two surfaces
rubbing against each other.#ra&ity 4 The force of attraction
between two objects.$ass 4 The amount of matter that an object is
made of, measured in kilograms 7kg9.thr%st 4 A force that pushes an
object forwards.%(thr%st 4 A force that pushes an object
upwards.wei#ht 4 The force caused by gra"ity acting on an object,
measured in newtons 789. Boardworks Ltd 20041 of 20 Boardworks Ltd
200523 of 245na#ra$s Boardworks Ltd 20041 of 20 Boardworks Ltd
200524 of 24/%!ti(!e6choice 0%i7
