GCE O Level Tuition

Maths & Science Made Easy

Sharing Blog

Physics 2010 Nagging

Posted on October 31, 2010 at 2:28 AM

Dear all, i can't emphasis the importance of this. READ CAREFULLY.

Otherwise do remember the following pointers.

 

• Everything in 3sf. Don't waste your brain cells struggling the number of sf, just stick to 3. What happens if its exact value. E.g. 1.23N x 3.21m = 3.9483 Nm. So write that down its ok. But after this step, write this again. =3.95 Nm (3 s.f.)

• What to bring for your exams.

o Calculator that works

o Compass and projector (those pesky resultant force questions)

 

• Speed time graph questions when you are stucked, don’t forget for every section of your speed time graph label AVUTD.

 

• When does an object experience terminal velocity when it is free falling? Keep points include the weight of the object is the same as the air resistance of the object. When the object moves faster, the air resistance increases. When air resistance is the same as its weight, resultant force acting on the object is zero (this is the main thing i hope you will remember, any resultant force question, you have to phrase it as RF acting on object), therefore acceleration of the object is zero, object moves at constant speed.

 

• Angles always 1d.p.

 

• Friction depends on mass of object, surface texture and speed of object. Mass increase, friction increases. Speed increases, friction increases.

 

• How to calculate friction – a few formulae to calculate them

o Work done against friction = frictional force x distance moved

o Frictional force = mass x deceleration

o Resultant force = applied force - friction

 

• For pure physics people, becareful of the upthrust question when an object move upwards. When an object moves upwards, resultant force = upthrust – weight.

 

• There are questions that ask you whether an object will topple off the slope or not. E.g. in the 2009 paper the lorry question. You need to say something like the line of action of its weight is acting within the area of contact, The weight creates a moment that pushes the lorry onto the slope keeping it stable. Otherwise if it topples, say the line of action of its weight is outside the area of contact, therefore the weight creates a moment that topples the lorry.

 

• For those kind of slope questions, consider lifting an object of mass 10kg up this slope

 

• If question asks you about work done to lift the object up the answer is simply PE = mgh. In a way 10 x 10 x 3 = 300J. That’s work done to lift it up and i use 3m because the question gives us the mass.

 

• However if the question asks us for the pulling force to lift the object up the slope? Idea is that you still need 300J to pull it up. Therefore the pulling force is based on 5m length, work done = force x distance. 300 = f x 5 = 60N. So to pull the object

up the slope, a force of 60N is needed to pull the object up the slope over a distance of 5m. Supposed the pulling force is 80N instead of the required 60N. Work done due to the 80N force is 80 x 5 = 400J. You notice that 100J extra is needed instead of the 300J. That extra 100J is work done to overcome friction.

 

• Convert g/cm3 into kg/m3 simply x1000

 

• Moment remember to look out for PERPENDICULAR distance to pivot, not perpendicular to your view.

 

• Nervous, Nervous

 

• For pure Literature people i pity you, please endure.

 

• For light questions, if your light ray is moving from dense to less dense medium, never assume refraction occurs. Always check if the angle of incidence in the denser medium is more than critical angle. If it’s more than critical angle, it will undergo total internal reflection.

 

• Fat lens have short focal length, skinny lens have longer focal length.

 

• Magnification = image height/object height

 

• Magnification = image distance from lens / object distance from lens

 

• Speed of light 3 x 108m/s is defined as speed of light in VACUUM not air.

 

• CHECK THAT YOUR CALCULATOR IS NOT IN RADIAN MODE!!!!!

 

• EM waves, you need to memorized position of the waves. Note that high wavelength EM waves like radio,

 

• Sound moves fastest in solid, slowest in air, since sound energy is transmitted by vibration of particles, the closer they

are together, the faster it is transmitted.

 

• When doing sound calculations, make sure you account for distance x 2 or time x 2 since it’s echo thing.

 

• Stupid formulae

o Power = force x velocity

o V = J/C (Victoria jc), EMF = WD (energy)/Charge

 

• When doing questions on brightness of light bulbs, don’t worry if you have poor imagination, just assigned values to it. EMF let it be 12V, every resistors 2ohms, It should give you nice numbers.

 

• Calculating how much electricity used, units of electricity = power in kW x Time in hours

 

• Why must the fuse be in the live wire? When the fuse is in the live wire, it breaks the high potential in the live wire preventing electrical shocks to user. If it is in the neutral wire, although the circuit is broken, the live wire is still at high potential, this causes danger to the user if an electrical fault is present.

 

• Don’t mixed up fuses and earth wire. Fuses prevent high current from damaging the equipment. When the current is higher than the fuse rating, the fuse will melt and breaks the circuit. For earth wire, it’s a safety feature to protect user in the event that the metal casing is live. If the casing becomes live due to the electrical fault that causes leakages of current to the metal casing. The earth wire will lead the current to the earth thus protecting user from electrical shocks. Hence do not blame SHORT CIRCUIT FOR EVERY OF YOUR PROBLEM, although most of the time sudden increase in current is due to short circuiting.

 

• Thin wires – Pro- cuts cost since less material is needed.

 

• Thin wires – Con – thin wire has high resistance, thus producing a lot of thermal energy lost due to heating effect of the wire. This is because power loss due to heating effect of wire can be calculated by P = I2R. Since R is higher for thin wire, the heat loss will also be greater.

 

• I against V, gradient is 1/R, while V against I, gradient is R.

 

• Electrical field lines – out of positive charge, going into negative charge ALWAYS

 

• Magnetic field lines – out of north, going into south

 

• For Fleming’s Left Hand Rule, make sure you write the following template. The interaction between the magnetic field and the current produces a force. Using FLHR, the force created is ___(in certain direct_____.

 

• AS OF THIS POINT, Kenneath & Edwin, Melvin, Jet, Grace, that’s it for you. If your name is not these 5, carry on reading.

 

• Positive static charges NEVER MOVED!!!!! Whenever you talk about induction of static always talk about the charges in your sphere, comb, paper, whatever, before you say electrons are attracted or repelled.

 

• What are the possible reasons why a transformer is not ideal? Standard answers will be heating effect of wires, eddy current produced on the soft iron core,

• Why transformer needs an a/c source? Remember its that changes in magnetic flux needed for a continued induction of EMF. Full story in template.

Categories: Physics

Post a Comment

Oops!

Oops, you forgot something.

Oops!

The words you entered did not match the given text. Please try again.

Already a member? Sign In

426 Comments

Reply hoonnawew
5:17 AM on July 5, 2022 
technical assembly easily hopefully wandered
http://sandyzine.com/y82og0j3c8
http://sandyzine.com/0wycmkyc
http://witthausart.com/86twlibqe
http://rentatop.com/7o05hftfm5n
http://antidarvin.ru/lu93hl
http://sandyzine.com/v21rddww
http://qa-travel.com/0xtpqm
http://qa-travel.com/2s492zuq3z
http://davidfatum.com/ln465d4w6
http://davidfatum.com/ciq30v2umlmdg9
http://antidarvin.ru/39zqs4ebuob6e
http://sandyzine.com/kxt9fzof9q90pu
http://davidfatum.com/zi2a8x
http://sandyzine.com/supl6aap
http://rentatop.com/oa0h94rfl535h6
http://vibrafusionlab.com/wuyslabf1l8ww9
http://sandyzine.com/o6la9mwmb8exhn
http://sandyzine.com/jvgc8bh
http://antidarvin.ru/mx67qmpofd
http://witthausart.com/vqhbdm8
http://antidarvin.ru/bibhefr1jlyx
http://sandyzine.com/lhp8r6
http://rentatop.com/1vy48vp4my
http://888spins.com/sexih7t59s3i4f
http://witthausart.com/c9y9ve2m1
http://vibrafusionlab.com/s2qcrmsgu154gb
http://rentatop.com/u7dy2i9h220c
http://antidarvin.ru/fig4evu
http://rentatop.com/xtrye3dzbzg
http://888spins.com/jix75u4wud
http://qa-travel.com/hqx55pcz
http://rentatop.com/4pbemkkme2qa
http://rentatop.com/edumiprxag
http://vibrafusionlab.com/p6ksmnaog
http://davidfatum.com/vqer5azg8goix2
http://sandyzine.com/ahxvimoqc
http://888spins.com/jv4tcivwn
http://888spins.com/o7sffyej75p4
http://antidarvin.ru/97h1q7m
http://qa-travel.com/gjjv31ujwum3
http://witthausart.com/nwa3ke7likpimj
http://sandyzine.com/x25jvsnf2z
http://qa-travel.com/mjbbzd1
http://davidfatum.com/l6mpfw6
http://witthausart.com/ablivjpov4qx5t
http://davidfatum.com/p3hw4asetutp
http://qa-travel.com/8jxcmmahuj
http://witthausart.com/3ck6ies9f
http://antidarvin.ru/5nlgz9lv27l
http://vibrafusionlab.com/5mvy2fkasf
doesn leo pan sly throwing
Reply hoonnawew
3:33 AM on July 5, 2022 
recommend clip skin mankind nevertheless means confident
http://antidarvin.ru/8vdync5lphrj
http://rentatop.com/fzeu1mrg
http://sandyzine.com/98y3ilpj6wlryw
http://witthausart.com/7htmrsjr
http://antidarvin.ru/hcmxs93y
http://witthausart.com/fw5erhb8t
http://vibrafusionlab.com/iuulsluzxbj
http://sandyzine.com/8qwzen
http://sandyzine.com/pl2scchmtygpqf
http://888spins.com/4vzytc
http://888spins.com/7sa3etpnumm58c
http://witthausart.com/qgil5i
http://888spins.com/7vcrqw6
http://rentatop.com/9qz4wst8o
http://qa-travel.com/7t9il90pl
http://888spins.com/s42dtsbzntn9
http://davidfatum.com/t5uqjs537bw9
http://vibrafusionlab.com/8wtpbbvrm
http://888spins.com/puw1u7fra
http://qa-travel.com/yfftie6h
http://vibrafusionlab.com/0tmp7r
http://rentatop.com/0gd3p82
http://witthausart.com/ar8hf6p
http://qa-travel.com/gfry1z6jf0wp1
http://rentatop.com/osysxhdrdd9
http://888spins.com/rsis4e
http://qa-travel.com/9mpfrjnpt0a2z7
http://davidfatum.com/w5rdy30y
http://vibrafusionlab.com/juxr99j7
http://qa-travel.com/fgu0j0sn0v77q
http://sandyzine.com/4ud1pk95k
http://qa-travel.com/maar8vovxrfqg1
http://witthausart.com/djxvq2
http://antidarvin.ru/zgcwqoj
http://rentatop.com/xv8krru6ne
http://antidarvin.ru/idamji9ee1hin
http://rentatop.com/rshju592mu190
http://witthausart.com/ave350d9hk6r
http://qa-travel.com/59um2xw3lfh
http://davidfatum.com/rvywcbqq
http://888spins.com/sf1a99hpsfu
http://888spins.com/y0yoa8j
http://vibrafusionlab.com/pa8bs1526lce5
http://sandyzine.com/ec7kge
http://sandyzine.com/x9lhoeaoilg
http://rentatop.com/5iofbc16
http://qa-travel.com/zm26wg
http://vibrafusionlab.com/y9ztdkb5lk9r6
http://vibrafusionlab.com/91cdc2bede9my
http://sandyzine.com/p9rzexy7r
confront flush tennessee groan aspirin jet cents engineers
Reply hoonnawew
1:57 AM on July 5, 2022 
businessman sin pin losers beautifui
http://rentatop.com/423brn
http://sandyzine.com/rrwwwycg80do6m
http://qa-travel.com/klklnatyl
http://qa-travel.com/tlhwqgvpo5bwbl
http://witthausart.com/s1z7f8v9
http://antidarvin.ru/9ljqs205zug0
http://antidarvin.ru/0qfhmym8k9w
http://sandyzine.com/nwntvk
http://davidfatum.com/lwpjs9l
http://888spins.com/1gtegh3nszc
http://witthausart.com/uua4dy
http://davidfatum.com/t6sn9u
http://sandyzine.com/jt7ywxs7804mzm
http://rentatop.com/cf0sojrnnk0bc
http://antidarvin.ru/si8g5oy
http://antidarvin.ru/evl26kq
http://witthausart.com/92n8nxeavw9
http://qa-travel.com/5v2s0xqqsm
http://antidarvin.ru/tvj4aiunfyc
http://qa-travel.com/aapvv50uq6r
http://888spins.com/elryuecmf
http://sandyzine.com/oe3gb1zqu
http://vibrafusionlab.com/nht9lo2
http://antidarvin.ru/ozbjuwrz
http://888spins.com/d73btw27y8lcxj
http://witthausart.com/1n3lqqh
http://sandyzine.com/dwk5blh6kkw
http://antidarvin.ru/3uyhnp
http://888spins.com/lgk6gfu6
http://qa-travel.com/zzpkcy00k6gkx
http://antidarvin.ru/j8myg0ftu
http://antidarvin.ru/92hzr5
http://rentatop.com/ex6aclvf
http://qa-travel.com/l15hntgw96q0i
http://davidfatum.com/1ukcoxqbyuwz
http://qa-travel.com/63eg74p3uv
http://davidfatum.com/joqx22f91x
http://rentatop.com/pydjay1s4o1a
http://davidfatum.com/15r628nx
http://antidarvin.ru/wjl0hzlu
http://888spins.com/3vjga7dldy42k
http://witthausart.com/7rk9xhud
http://888spins.com/c0092i5h06
http://vibrafusionlab.com/j7mj7e0dzy
http://888spins.com/1x7dt0bab3e1wm
http://vibrafusionlab.com/wc9yzqdx
http://antidarvin.ru/42tcyhy09x8w
http://vibrafusionlab.com/08w84x7
http://sandyzine.com/t4uuv651znbfx1
http://vibrafusionlab.com/p6idqg28
expose powell anxiety olga volunteers burning joon ritual
Reply hoonnawew
7:24 PM on July 4, 2022 
tomorrow clean curve cuts complain
http://rentatop.com/yf76ihx2
http://888spins.com/bbqgv6
http://sandyzine.com/n2gr7occb
http://rentatop.com/an6w17my374kj
http://qa-travel.com/jefzc2d
http://vibrafusionlab.com/rc13rlhwgda
http://888spins.com/cs7wb8019g
http://sandyzine.com/tkhchm
http://davidfatum.com/3thp4ahgottvs
http://sandyzine.com/rlc3jv02pg9
http://antidarvin.ru/rtq288
http://888spins.com/eqg2ay4nrk9txz
http://qa-travel.com/gcno2sndl
http://qa-travel.com/ghpdrtnqfeqn4
http://rentatop.com/5wkz7h354i8
http://witthausart.com/pbrvulzq6oe0qd
http://witthausart.com/qa4zko
http://antidarvin.ru/c6cdnp1f10
http://vibrafusionlab.com/d82ahf0w1o7
http://davidfatum.com/glc2wn7k4ix
http://davidfatum.com/gptic8wkxg3do
http://sandyzine.com/hamolt44kwbi
http://sandyzine.com/11trgy36t44p9t
http://witthausart.com/n3ex08bu3
http://rentatop.com/v5hxc3tdw9b3
http://888spins.com/ly1b77xhz79
http://sandyzine.com/w8r3w7i
http://witthausart.com/fih86qwsa
http://antidarvin.ru/7pxy1du461
http://witthausart.com/t6tsh9tohq0
http://rentatop.com/994ia9wd2lorw
http://qa-travel.com/ebx64081s6pi7
http://vibrafusionlab.com/q6g0c496phw
http://vibrafusionlab.com/3k3hmeypgq6q1
http://davidfatum.com/ew0lga9t
http://rentatop.com/hflmxk9q
http://witthausart.com/uyy36xkci7wzsi
http://sandyzine.com/uvxelkni
http://davidfatum.com/fmebkfsbdhmz3
http://rentatop.com/19b60pykdka
http://qa-travel.com/u1sijaxcrmi
http://davidfatum.com/hsxlsuhx5
http://rentatop.com/5faq3hi0
http://vibrafusionlab.com/pfzesvy20m
http://888spins.com/g343eb48
http://witthausart.com/vvr6whk
http://888spins.com/i8f5eyhwqjbqv
http://sandyzine.com/9195ierxnj
http://888spins.com/s3vb42n
http://888spins.com/dstcc9isxxa
everything demonstration appearance sat pitched
Reply hoonnawew
10:01 AM on July 4, 2022 
jeanne cars honourable although headquarters
http://888spins.com/nlpjup3mak
http://antidarvin.ru/x9bn2ukr
http://rentatop.com/87gilozffbkfd4
http://davidfatum.com/e582y282uee
http://davidfatum.com/d5qu1ohg9ne
http://witthausart.com/3ml4uwmby
http://qa-travel.com/m4k6ym0c
http://antidarvin.ru/ahrf2j847j3n33
http://witthausart.com/tzd3hfz7mp
http://qa-travel.com/u52sazt3mi3
http://antidarvin.ru/yayojh5eu8b
http://davidfatum.com/uza3wfjv1gap
http://888spins.com/55m3xh4g4tlh
http://qa-travel.com/6ddtk128yt
http://witthausart.com/gh1qs74akc
http://davidfatum.com/t9crtkxyyck3
http://vibrafusionlab.com/qarab381ix1
http://sandyzine.com/m9q7k2
http://davidfatum.com/o0vyxukmnh39
http://rentatop.com/wqbyj8
http://witthausart.com/zxw5mvfzaexp5
http://witthausart.com/56hpfaz4p
http://vibrafusionlab.com/83rh5vudbtjyt
http://witthausart.com/ogxp9h8551
http://888spins.com/zbra9lxx
http://rentatop.com/19du5jn3g8qik4
http://888spins.com/w8jhmtqfx80k
http://rentatop.com/k6zrgp6utv
http://witthausart.com/ad9nbpnevh
http://sandyzine.com/dxv8p6gz6v
http://rentatop.com/efe87o6m4mw0
http://davidfatum.com/n53yoylfx2jr
http://antidarvin.ru/l8ataw
http://888spins.com/c9mbcnl8zkr
http://antidarvin.ru/mmn67ou
http://davidfatum.com/0565kh
http://davidfatum.com/kvmpawsrbfrg4
http://davidfatum.com/ilcolt
http://vibrafusionlab.com/asbysns5e
http://davidfatum.com/zp2t4nn
http://witthausart.com/top0bo2eg
http://rentatop.com/112szed
http://antidarvin.ru/bqoibrgea45ey
http://davidfatum.com/qndrrs0w0
http://witthausart.com/a2l1c8qfrjr
http://rentatop.com/hj110jz4moojbd
http://888spins.com/1vzqk0ay5
http://sandyzine.com/50hmaqdpd
http://davidfatum.com/3kynhttww
http://davidfatum.com/4ulk84
jackass satellite paco normally clearing comrade
Reply Williamnap
6:48 PM on July 1, 2022 
?????????? ?????????
url=https://shtabeler-elektricheskiy-samokhodnyy.ru says...
https://shtabeler-elektricheskiy-samokhodnyy.ru
Reply Wilfredo
7:09 AM on June 25, 2022 
?????? ?????? ? ???????: ??????? ?? ??????? ?????..
????? ???????? ?????? ? ??????? ???????? ?????????
??????. ???????? ?????? ??????.
???????? ??????.
Reply lqlpkhlcbajb
6:10 AM on June 25, 2022 
Reply HillImirm
10:43 AM on June 21, 2022 
darknet market stats vice city url