#separator:tab
#html:true
what is hooke's law? the extension of a material is proportional to the applied
force provided the limit of proportionality is not exceeded
what is hooke's law equation? F=kx <br>F= force applied N<br>k= spring
constant N/cm<br>x= extension cm
key tips about spring constant <ul><li>the spring constant is value specific
for each spring</li></ul>
what is the limit of proportionality? the last point on the graph where the
force and extension are directly proportional, beyond this point the graph begins
to curve + hooke's law no longer applies
what is the elastic limit? maximum load a specimen can experience and still
return to its original length when the applied load is removed, if the specimen
returns to its original length this is known as elastic deformation
hooke's law graph "<img src=""4-5-hookes-law-graph_edexcel-al-physics-rn.png"">"
what is the yield point? when a material stretched beyond it's elastic limit
reaches the yield point, the internal molecular structures is being permanently
altered
what is plastic deformation? once a material has exceeded its elastic limit we say
it undergoes plastic deformation - it will not return to its original length/shape
what are the series/parallel spring combos "series: (hanging down on
each other)<br><ul><li>x<sub>1</sub>=F/k<sub>1</sub>,
x<sub>2</sub>=F/k<sub>2</sub></li><li>x<sub>t</sub>=x<sub>1</sub>+x<sub>2</sub></
li><li>1/k<sub>t = </sub>1/k<span style=""font-size: 16.6667px;"">1
+ </span>1/k<span style=""font-size:
16.6667px;"">2</span><br></li><li>x<sub>t</sub>=F/k<sub>t </sub></li></
ul><div>parallel: (hanging together)<br></div><div><ul><li>F<sub>t
=</sub> F<sub>1</sub>+F<sub>2</sub></li><li>k<sub>t = </sub>k1
+ k2</li><li>F<sub>1
= </sub><sub> </sub>k1x<br></li><li>F2<sub> = </
sub><sub> </sub>k2x</li></ul></div>"
what is stress? (definition) the applied force per unit area of cross section
what is stress? (equation + measured) ø=F/A<br>it is measured in Nm<sup>-
2 </sup> or Pascals
what is ultimate tensile stress? the maximum stretching force per unit area the
material can undergo without breaking
what is strain? (definition) the strain on a material is defined as the ratio of
its extension and it's original length
what is strain? (equation + measured in?) E=∆L/L<br> this doesn't have units
what is young's modulus (definition)? ratio of stress acting on a substance to
the strain produced
what is young's modulus? (equation + measured in) E = ø/∑<br>measured a newton
per square metre (Nm<sup>-2 </sup>or Pa)
what are strain energy equations? E = .5kx<sup>2<br></sup>E = Fkx
young's modulus experiment (diagram) "<img src=""Screenshot 2023-02-23 at
20.23.58.png"">"
young's modulus experiment (method) <ul><li>set up apparatus as shown</li><li>use a
small piece of gummed paper as marker</li><li>measure the OG length of wire using a
tape measure from clamp to marker</li><li>use a screq gauge mirometer to measure
diameter or the wire in 5 places</li><li>find average</li><li>calculate area
(πd<sup>2</sup>)/4</li><li>load the wire in 2N</li><li>use travelling microscope
and find extension continue loading until wire snaps</li><li>plot a graph of load
(y) against extension (x)</li></ul>
young's modulus experiment (graph) "<img src=""media-57a-57a797a6-03aa-4fd6-9136-
0857d8c56b42-phpUUZosH.png"">"
young's modulus experiment (mapped) <ul><li>grad =
rise/run</li><li>A=πd<sup>2</sup>/4</li><li>g=EA/L</li><li>grad=EA/L</li><li>E=FL/
Ax</li><li>y=mx+c</li><li>F=EA/L (x) + 0</li></ul>
young's modulus experiment (graph equation) E=FL/Ax OR F=EA/L (x)<br><ul><li>E;
, Young's M Nm<sup>-2</sup></li><li>F; Force N</li><li>L; original length
m</li><li>A; cross sectional area m<sup>2</sup> </li><li>x; extension
m</li></ul>
what is a plum pudding? <ul><li>positive uniform sphere</li><li>negative charges
dotted around like currents</li></ul>
what is the rutherford (nuclear model) "<a href=""https://www.google.com/imgres?
imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fe
%2Fe8%2FRutherford_atomic_planetary_model.svg&imgrefurl=https%3A%2F
%2Fen.wikipedia.org%2Fwiki
%2FRutherford_model&tbnid=EMBLGWdlLOwRUM&vet=12ahUKEwi0zrCGwKz9AhWHmycCHYkO
DUkQMygAegUIARDLAQ..i&docid=vL4GGlJ8k2B6uM&w=500&h=500&q=what%20is
%20the%20rutherford%20(nuclear
%20model)&client=safari&ved=2ahUKEwi0zrCGwKz9AhWHmycCHYkODUkQMygAegUIARDLAQ
""><div><img alt=""Rutherford model - Wikipedia"" src=""paste-
23886ee61a50e97cd1319e345cced5fcd818e411.png""></div></a>"
what is the rutherford (experiment) "<img src=""paste-
be745b3a497a3ad2034d9c129ef5979e1bff18ac.jpg""><br><ul><li>vaccum</li><li>gold
foil</li><li>travelling microscope</li><li>deflection</li><li>an eye</li><li>zinc
sulphide screen</li><li>back scattered alpha particles</li><li>source</li></ul>"
what happens? (rutherford) a beam of alpha particles is directed at a thin gold
film in a vaccum
why does rutherfold happen in a vaccum? prevents interaction between alpha and
air particles
what happens? (general explain in nuclear) alpha particles interact with atoms
in the gold and then strikes the zinc sulphide screen causing a flash of light to
appear, this allows for deflection of alpha particles after having passed through
atoms
what happens? (thomsom's) majority of atoms would have passed through the foil
undeflected, a small number MAY have been deflected through small angles
diagrams of nucleus in deflection + explain "<img src=""paste-
acbc3cf8e9aff710a2642517edebc05e708a6031.jpg""><br><ul><li>large volume of empty
space</li><li>alpha did not come close to be deflected</li><li>those deflected
through large angles must come close to a similarily charged particles</li></ul>"
size of nucleus (assumptions, equations + periodic element)<ul><li>volume of
protons + neutrons are small</li><li>nucleus is spherical</li><li>\[r =
roA^1/3\]</li><li>r: radius of nucleus</li><li>ro; radius of a singular
nucleon</li><li>A; mass number of
nucleus</li></ul><div><sup>A</sup><sub>Z</sub>X</div><div>A; mass number
(p+n)</div><div>Z; atomic number (p)</div>
graphs for nucleus radius "<div><a href=""https://www.google.com/imgres?
imgurl=https%3A%2F%2Frevise.im%2Fcontent%2F02-physics%2F04-unit-5%2F01-
radioactivity%2Fradius_nucleon.png&imgrefurl=https%3A%2F%2Frevise.im%2Fphysics
%2Funit-5%2Fradioactivity&tbnid=cmCI-
PkMwFnCzM&vet=12ahUKEwiVxvKUw6z9AhX4W6QEHQVPCvwQMygFegUIARC_AQ..i&docid=Eqj
XW82pnOOVuM&w=700&h=632&q=graphs%20for%20nucleus%20radius
%20&client=safari&ved=2ahUKEwiVxvKUw6z9AhX4W6QEHQVPCvwQMygFegUIARC_AQ""><im
g alt=""Radioactivity - Revise.im"" src=""paste-
4540a4158f1fd143f809a996a45e1a8ddeaaafa1.png""></a><img src=""paste-
c3c1d818e77d6e4dabe0fe6a9637a9b216f86714.jpg""></div><div><br></div>"
what is nuclear decay? a process in which nuclei rearrange themselves to become
more stable by emitting radiation
what is ionisation? the loss or gain of an electron by an atom
how do decay particles lose KE after released into atmosphere <ul><li>collisions
w/particles in air causing energy to be transferred and an overall reduction in
their KE</li></ul>
why do alpha particles have a shorter range in air than the beta particle even
though it's released w/more KE <ul><li>alpha particles have a larger mass so
they travel slower than beta</li><li>alpha particles have a larger, chance to
collide w/air particles more frequently than smaller beta particles</li></ul>
#html:true
what is hooke's law? the extension of a material is proportional to the applied
force provided the limit of proportionality is not exceeded
what is hooke's law equation? F=kx <br>F= force applied N<br>k= spring
constant N/cm<br>x= extension cm
key tips about spring constant <ul><li>the spring constant is value specific
for each spring</li></ul>
what is the limit of proportionality? the last point on the graph where the
force and extension are directly proportional, beyond this point the graph begins
to curve + hooke's law no longer applies
what is the elastic limit? maximum load a specimen can experience and still
return to its original length when the applied load is removed, if the specimen
returns to its original length this is known as elastic deformation
hooke's law graph "<img src=""4-5-hookes-law-graph_edexcel-al-physics-rn.png"">"
what is the yield point? when a material stretched beyond it's elastic limit
reaches the yield point, the internal molecular structures is being permanently
altered
what is plastic deformation? once a material has exceeded its elastic limit we say
it undergoes plastic deformation - it will not return to its original length/shape
what are the series/parallel spring combos "series: (hanging down on
each other)<br><ul><li>x<sub>1</sub>=F/k<sub>1</sub>,
x<sub>2</sub>=F/k<sub>2</sub></li><li>x<sub>t</sub>=x<sub>1</sub>+x<sub>2</sub></
li><li>1/k<sub>t = </sub>1/k<span style=""font-size: 16.6667px;"">1
+ </span>1/k<span style=""font-size:
16.6667px;"">2</span><br></li><li>x<sub>t</sub>=F/k<sub>t </sub></li></
ul><div>parallel: (hanging together)<br></div><div><ul><li>F<sub>t
=</sub> F<sub>1</sub>+F<sub>2</sub></li><li>k<sub>t = </sub>k1
+ k2</li><li>F<sub>1
= </sub><sub> </sub>k1x<br></li><li>F2<sub> = </
sub><sub> </sub>k2x</li></ul></div>"
what is stress? (definition) the applied force per unit area of cross section
what is stress? (equation + measured) ø=F/A<br>it is measured in Nm<sup>-
2 </sup> or Pascals
what is ultimate tensile stress? the maximum stretching force per unit area the
material can undergo without breaking
what is strain? (definition) the strain on a material is defined as the ratio of
its extension and it's original length
what is strain? (equation + measured in?) E=∆L/L<br> this doesn't have units
what is young's modulus (definition)? ratio of stress acting on a substance to
the strain produced
what is young's modulus? (equation + measured in) E = ø/∑<br>measured a newton
per square metre (Nm<sup>-2 </sup>or Pa)
what are strain energy equations? E = .5kx<sup>2<br></sup>E = Fkx
young's modulus experiment (diagram) "<img src=""Screenshot 2023-02-23 at
20.23.58.png"">"
young's modulus experiment (method) <ul><li>set up apparatus as shown</li><li>use a
small piece of gummed paper as marker</li><li>measure the OG length of wire using a
tape measure from clamp to marker</li><li>use a screq gauge mirometer to measure
diameter or the wire in 5 places</li><li>find average</li><li>calculate area
(πd<sup>2</sup>)/4</li><li>load the wire in 2N</li><li>use travelling microscope
and find extension continue loading until wire snaps</li><li>plot a graph of load
(y) against extension (x)</li></ul>
young's modulus experiment (graph) "<img src=""media-57a-57a797a6-03aa-4fd6-9136-
0857d8c56b42-phpUUZosH.png"">"
young's modulus experiment (mapped) <ul><li>grad =
rise/run</li><li>A=πd<sup>2</sup>/4</li><li>g=EA/L</li><li>grad=EA/L</li><li>E=FL/
Ax</li><li>y=mx+c</li><li>F=EA/L (x) + 0</li></ul>
young's modulus experiment (graph equation) E=FL/Ax OR F=EA/L (x)<br><ul><li>E;
, Young's M Nm<sup>-2</sup></li><li>F; Force N</li><li>L; original length
m</li><li>A; cross sectional area m<sup>2</sup> </li><li>x; extension
m</li></ul>
what is a plum pudding? <ul><li>positive uniform sphere</li><li>negative charges
dotted around like currents</li></ul>
what is the rutherford (nuclear model) "<a href=""https://www.google.com/imgres?
imgurl=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fe
%2Fe8%2FRutherford_atomic_planetary_model.svg&imgrefurl=https%3A%2F
%2Fen.wikipedia.org%2Fwiki
%2FRutherford_model&tbnid=EMBLGWdlLOwRUM&vet=12ahUKEwi0zrCGwKz9AhWHmycCHYkO
DUkQMygAegUIARDLAQ..i&docid=vL4GGlJ8k2B6uM&w=500&h=500&q=what%20is
%20the%20rutherford%20(nuclear
%20model)&client=safari&ved=2ahUKEwi0zrCGwKz9AhWHmycCHYkODUkQMygAegUIARDLAQ
""><div><img alt=""Rutherford model - Wikipedia"" src=""paste-
23886ee61a50e97cd1319e345cced5fcd818e411.png""></div></a>"
what is the rutherford (experiment) "<img src=""paste-
be745b3a497a3ad2034d9c129ef5979e1bff18ac.jpg""><br><ul><li>vaccum</li><li>gold
foil</li><li>travelling microscope</li><li>deflection</li><li>an eye</li><li>zinc
sulphide screen</li><li>back scattered alpha particles</li><li>source</li></ul>"
what happens? (rutherford) a beam of alpha particles is directed at a thin gold
film in a vaccum
why does rutherfold happen in a vaccum? prevents interaction between alpha and
air particles
what happens? (general explain in nuclear) alpha particles interact with atoms
in the gold and then strikes the zinc sulphide screen causing a flash of light to
appear, this allows for deflection of alpha particles after having passed through
atoms
what happens? (thomsom's) majority of atoms would have passed through the foil
undeflected, a small number MAY have been deflected through small angles
diagrams of nucleus in deflection + explain "<img src=""paste-
acbc3cf8e9aff710a2642517edebc05e708a6031.jpg""><br><ul><li>large volume of empty
space</li><li>alpha did not come close to be deflected</li><li>those deflected
through large angles must come close to a similarily charged particles</li></ul>"
size of nucleus (assumptions, equations + periodic element)<ul><li>volume of
protons + neutrons are small</li><li>nucleus is spherical</li><li>\[r =
roA^1/3\]</li><li>r: radius of nucleus</li><li>ro; radius of a singular
nucleon</li><li>A; mass number of
nucleus</li></ul><div><sup>A</sup><sub>Z</sub>X</div><div>A; mass number
(p+n)</div><div>Z; atomic number (p)</div>
graphs for nucleus radius "<div><a href=""https://www.google.com/imgres?
imgurl=https%3A%2F%2Frevise.im%2Fcontent%2F02-physics%2F04-unit-5%2F01-
radioactivity%2Fradius_nucleon.png&imgrefurl=https%3A%2F%2Frevise.im%2Fphysics
%2Funit-5%2Fradioactivity&tbnid=cmCI-
PkMwFnCzM&vet=12ahUKEwiVxvKUw6z9AhX4W6QEHQVPCvwQMygFegUIARC_AQ..i&docid=Eqj
XW82pnOOVuM&w=700&h=632&q=graphs%20for%20nucleus%20radius
%20&client=safari&ved=2ahUKEwiVxvKUw6z9AhX4W6QEHQVPCvwQMygFegUIARC_AQ""><im
g alt=""Radioactivity - Revise.im"" src=""paste-
4540a4158f1fd143f809a996a45e1a8ddeaaafa1.png""></a><img src=""paste-
c3c1d818e77d6e4dabe0fe6a9637a9b216f86714.jpg""></div><div><br></div>"
what is nuclear decay? a process in which nuclei rearrange themselves to become
more stable by emitting radiation
what is ionisation? the loss or gain of an electron by an atom
how do decay particles lose KE after released into atmosphere <ul><li>collisions
w/particles in air causing energy to be transferred and an overall reduction in
their KE</li></ul>
why do alpha particles have a shorter range in air than the beta particle even
though it's released w/more KE <ul><li>alpha particles have a larger mass so
they travel slower than beta</li><li>alpha particles have a larger, chance to
collide w/air particles more frequently than smaller beta particles</li></ul>
