> ~}7 ]bjbjUU .L77llVVVjDDDD`j>00000www$R rVwwwwwx00ZΆxxxw0V0xwx
x'hV'0$ :,=jDwd''l0'x'xjjFORCES AND ENERGY NAME ........................................
Suppose that you have three clockwork trains, all of the same mass but with their springs all wound up differently. The more the spring is wound up the more energy is stored in it.
Train 1 has 1 unit of stored energy, train 2 has 2 units of stored energy and train 3 had 3 units of stored energy. All three trains are now allowed to run along a straight, level track until they stop  they will then have used up all their stored energy.
We find that the first train with 1 unit of stored energy goes 30 m before it stops.
The train stops because it has used up its stored energy in doing work against the FRICTIONAL FORCE that is trying to slow it down. This energy is converted to heat.
How far will the other trains go before they stop if the force of friction on all of them is the same?
Complete the following table.
Units of stored energyFrictional forceDistance travelled (m)11302131
If the trains were twice as heavy the force of friction would be twice as big and if they were three times as heavy it would be three times as big.
Complete the tables below to show how far the trains would go now.
Units of stored energyFrictional forceDistance travelled (m)122232
Units of stored energyFrictional forceDistance travelled (m)132333
The energy used up by the train controls the distance travelled and this distance is also affected by the force that the train has to overcome. The train has used up some stored energy and has done work against a frictional force.
Complete the following table to help to see the connection between energy, force and distance travelled.
Units of stored energyFrictional forceDistance travelled (m)Force x Distance111213212223313233
From these results you should see that the connection is as follows.
(Copy the section in the next two boxes into your books.
FORCES AND ENERGY NAME: .......................................
Complete the following table:
Energy changed (J)Force (N)Distance travelled (m)530212120.250.5201622052463612483
LIFTING WEIGHTS
The earth pulls on every object at its surface with a force that w call the weight of the object.
The force of the Earth on every kilogram at its surface is about 10 Newtons.
We usually write the strength of the Earths field as 10 N/kg
What is the weight in Newtons of:
(a) 45 kg(b) 50 kg(c) 6.7 kg(d) 560 g
When you lift up a 1 kg mass a distance of 1m you change 10 J of chemical energy in your body to 10 J of potential energy (ignoring heat for the moment).
Complete the following table about lifting weights.
MassWeight (N)Height liftedEnergy changed (J)6 kg2m5 kg4m250 g6m12012000.6 kg60 cm36960 kg600255200010 000
1
2
QUANTITY OF ENERGY = FORCE x DISTANCE TRAVELLED
In other words a certain amount of energy has been changed from one form to another and a certain amount of work has been done.
FORCE is measure in NEWTONS and DISTANCE in METRES.
ENERGY is measured in units called JOULES (J).
So: JOULES = NEWTONS x METRES
One joule of energy is changed from one form to another when a force of one newton moves one metre.
Here are a few examples:
1 joule = 1 newton x 1 metre
2 joules = 2 Newtons x 1 metre OR 1 newton x 2 metres
4 joules = 4 Newtons x 1 metre OR 2 Newtons x 2 metres etc.
8 joules = 8 Newtons x 1 metre OR 4 Newtons x 2 metres etc.
and so on!
1
3
2
L M N S T Y Z _ `
!%(,/36:=AⴤjUmHnHuCJOJPJQJ^JCJ PJCJPJCJ OJPJQJ^JCJOJPJQJ^J5CJOJPJQJ\^J(jOJPJQJU^JmHnHsH uCJOJPJQJ^J#5B*CJOJPJQJ\^Jph6LM ^_n $$Ifa$$If$a$l\} ttt}ttt}ttt} $$Ifa$$$IfTlFM!OJ
064
la
w l$$IfTlFi
#
K A
064
la $$Ifa$$If
% 6 }ttt}ttt}rlt$If $$Ifa$$$IfTlFi
#
K A
064
la6 M N P R S T V X Y Z \ ^ _ ttt$$IfTlFi
#
K A
064
la $$Ifa$
_ ` a H
I
J
}{v{{{{mmmm $$Ifa$$a$$$IfTlFi
#
K A
064
la
lcccc $$Ifa$$$Ifl\
$
2 064
lalcccclccccl $$Ifa$$$Ifl\
$
2 064
la !#%&'(*cc$$Ifl\
$
2 064
la $$Ifa$*,./134568:cc$$Ifl\
$
2 064
la $$Ifa$:;<=?ABCDEFccaaa$$Ifl\
$
2 064
la $$Ifa$23FPg $$Ifa$3ghnouv
"#./>?FGST[\jlnoqsOQSUWXZ\ͣ5\5B*CJ(OJQJ\^JphCJOJPJQJ^JCJOJPJQJ^J5CJOJPJQJ\^JB*CJOJPJQJ^JphjUmHnHuCJOJPJQJ^J@ghiknopruvy~vvvvvv(vvv$ $$Ifa$$$IflF]&%064
la
vvv$$IflF]&%064
la $$Ifa$
v vvtt$$IflF]&%064
la $$Ifa$
"
o
$If
$$Iflִ_*
X$!%06 4
la
a,a,$$Ifl\+ Y% 064
la $$Ifa$!"#$c0c0$$Ifl\+ Y% 064
la $$Ifa$$()./67=>?@Cc@c $$Ifl\+ Y% 064
la $$Ifa$CDFGMNOSTUXYc4c $$Ifl\+ Y% 064
la $$Ifa$Y[\]bcjklnoc<ca__$$Ifl\+ Y% 064
la $$Ifa$
oqrs&Z,FGiJKLMNO$a$OPQSTUWXZ[\]$a$\]CJOJPJQJ^J,1h. A!"#$%
i8@8NormalCJ_HaJmH sH tH <A@<Default Paragraph Font<Z@<
Plain TextCJOJQJ^JaJ8]d8]LLM ^_nw
%6MNPRSTVXYZ\^_`aHIJ
!#%&'(*,./134568:;<=?ABCDEF23FPghiknopruvy~" o
!"#$()./67=>?@CDFGMNOSTUXY[\]bcjklnoqs&Z,

F
G
i
JKLMNOPQSUWXZ^000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000\]
% 6 _ *:g
$CYoO]
!"#$\D@~Z@Z(
T
C
T
C
h
SjJ"
N
3jJ
NX@
((
`B
c$DjJ((:h
#"g
mHn HJ%
#"` +#
#H%3Lt j
C##"S!+#`
c$vd@]j`
c$vd@Lt j
##"`
c$vd@]j`
c$vd@Z J_%
J_%D` P!
#W"J$f
s*v2@!
f
s*2@P!0Z
s
BCDEPF*v2@1O.d;3{1sQhT@ `#"uh` b_%
#b_%H
#333
%H
#*_%Z b%
b%l
0vd@1"%T
CjJ(#T
C1bT
C1]V#`
c$@1z8T2
C1HPT2
C1$HT2
C1#H#T2
C1 H ` "
#1%t T^
##"R\Z J
J Z J
JT
C1JZ
S1G:t J
#t.#"WT
C1JZ
S1GZr
SG
1T^T2
C1hgt T^
##"Z J
J Z J
JT
C1JZ
S1G:t J
#t.#"WT
C1JZ
S1GZr
SG
1T^T2
C1hgt T^
##"oZ J
J Z J
JT
C1JZ
S1G:t J
#t.#"WT
C1JZ
S1GZr
SG
1T^T2
C1hgt T^
##"l"Z J
J Z J
JT
C1JZ
S1G:t J
#t.#"WT
C1JZ
S1GZr
SG
1T^T2
C1hgr
s*PF0*PF0*8;E*
&n
#"
.Z
!
` +#
"# G
Lt j
#C##"S!+#`
$
c$vd@]j
`
%
c$vd@
Lt j
&##"`
'
c$vd@]j
`
(
c$vd@
Z
)
D` P!
*#!tf
+
s*v2@!
f
,
s*2@P!0
Z

s
BCDEPF*v2@1O.d;3{1sQhT@ `#"o
Z
.
H
/
#333 f
H
0
#
Z g
1g l
2
0vd@1cg
T
3
CjJzp
T
4
C1
T
5
C1Le
`
6
c$@1c8
T2
7
C1At
T2
8
C1A t
T2
9
C1eAt
T2
:
C1AKt
` "
;#=k
t T^
<##"R\Z J
=J Z J
>JT
?
C1J
Z
@
S1G
:t J
A#t.#"WT
B
C1J
Z
C
S1G
Zr
D
SG
1T^
T2
E
C1hg
t T^
F##"Z J
GJ Z J
HJT
I
C1J
Z
J
S1G
:t J
K#t.#"WT
L
C1J
Z
M
S1G
Zr
N
SG
1T^
T2
O
C1hg
t T^
P##"oZ J
QJ Z J
RJT
S
C1J
Z
T
S1G
:t J
U#t.#"WT
V
C1J
Z
W
S1G
Zr
X
SG
1T^
T2
Y
C1hg
t T^
Z##"l"Z J
[J Z J
\JT
]
C1J
Z
^
S1G
:t J
_#t.#"WT
`
C1J
Z
a
S1G
Zr
b
SG
1T^
T2
c
C1hg
r
d
s* PF0*PF0*eT
&n QeWi
e#"
&.Z QeWi
fQeWi` +#
g#Q@WLt j
hC##"S!+#`
i
c$vd@]j `
j
c$vd@ Lt j
k##"`
l
c$vd@]j `
m
c$vd@ Z ei
neiD` P!
o#e$f
p
s*v2@!
f
q
s*2@P!0 Z
r
s
BCDEPF*v2@1O.d;3{1sQhT@ `#"u! Z q
sqH
t
#333H H
u
#n Z qf
vqfl
w
0vd@1Of T
x
CjJ\T T
y
C1qMe T
z
C1S `
{
c$@1y T2

C1;o$ T2
}
C1a$ T2
~
C1$$ T2
C1$ ` "
#it T^
##"R\Z J
J Z J
JT
C1J Z
S1G :t J
#t.#"WT
C1J Z
S1G Zr
SG
1T^ T2
C1hg t T^
##"Z J
J Z J
JT
C1J Z
S1G :t J
#t.#"WT
C1J Z
S1G Zr
SG
1T^ T2
C1hg t T^
##"oZ J
J Z J
JT
C1J Z
S1G :t J
#t.#"WT
C1J Z
S1G Zr
SG
1T^ T2
C1hg t T^
##"l"Z J
J Z J
JT
C1J Z
S1G :t J
#t.#"WT
C1J Z
S1G Zr
SG
1T^ T2
C1hg r
s*PF0*PF0*
B
S ?]tutI#14 T,$Thll^n l
?B^333333Keith GibbsPC:\My Documents\Resourcefulphysics\Foundation level problems\Trains problems.docKeith GibbsC:\My Documents\Kerry 26th Feb 2004\(j) Foundation level problems  students,1114,problems  teachers,1114,problems\trains_problems.docKeith GibbsC:\My Documents\Resourcefulphysics\(o) Intermediate level problems  students,1416,problems  teachers,1416,problems\trains.docKeith GibbsC:\My Documents\Resourcefulphysics\(o) Intermediate level problems  students,1416,problems  teachers,1416,problems\trains.docGibbsfC:\Documents and Settings\Keith\My Documents\Resourcefulphysics\Intermediate level problems\trains.docGibbsEC:\Documents and Settings\Keith\My Documents\Files to send\trains.docGibbs<E:\Resourcefulphysics\Intermediate level problems\trains.docGibbs<E:\Resourcefulphysics\Intermediate level problems\trains.docGibbsEC:\Documents and Settings\Keith\My Documents\Files to send\trains.docGibbsaC:\Documents and Settings\Keith\My Documents\Schoolphysics\Intermediate level problems\trains.doc
%6MNPRSTVXYZ\^_`
!#%&'(*,./134568:;<=?ABCD3FPghiknopruvy~
!"#$()./67=>?@CDFGMNOSTUXY[\]bcjk^@=]P@UnknownGz Times New Roman5Symbol3&z ArialG
MS Mincho3 fg?5 z Courier New"hɦ֩k !Z20d2Trains mechanicstrains, forces, energyKeith GibbsGibbsOh+'08H Xd
Trains
mechanics Keith Gibbstrains, forces, energy=Force and energy using a set of trains  fill in the spaces.iNormalnGibbsn5bbMicrosoft Word 9.0i@F#@$@,=k ՜.+,0
px
1416TrSchoolphysicsc
TrainsTitle
!"#$%&()*+,./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklnopqrstvwxyz{Root Entry F,=1Table'WordDocument.LSummaryInformation(mDocumentSummaryInformation8uCompObjjObjectPool,=,=
FMicrosoft Word Document
MSWordDocWord.Document.89q