ngsjpftpay;

Ntiy> rf;jp kw;Wk; tY

(Work, Energy and Power)

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

NjHr;rp : 2.0 ngsjpftpay; Nfhl;ghLfspd; mbg;gilapy; vk;ikr; #oTs;s ,af;fq;fis gFg;gha;T nra;tjw;fhf mbj;jsj;ij ,LthH.

Ntiy> rf;jp kw;Wk; tY (Work, Energy and Power)

NjHr;rp kl;lk; : 2.5 rf;jpg; gad;ghL> CLflj;jy; vd;gtw;iw mstwpKiwapy; nra;thu;.

Ntiy nra;tjw;Fupa Mw;wy; rf;jp vdg;gLk;. rf;jp Ntiy Mjyhy; rf;jpapd; myF> gupkhzq;fs; KiwNa Ntiyapd; myF> gupkhzq;fis xj;jJ.

NeH Nfhl;L ,af;fj;jpy; khwh tpirapdhy; nra;ag;gLk; Ntiy

tpirapd; jpirapy; nghUs; mire;j J}uk;

= tpir X

W = F X S

SI myF J

gupkhzk; ML2T -2 Ntiy XH vz;zpf; fzpakhFk;.

NeH Nfhl;L ,af;fj;jpy; nra;ag;gLk; Ntiy (Work done in linear motion)

F

S

W = F X S

W = F S cosθ

Ntiy (Work)

rf;jp (Energy)

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

nghwpKiw rf;jp Mechanical Energy

nghwpKiw rf;jp gy tbtq;fspy; fhzg;gLk;.

01

,af;fg;ghl;L rf;jp Kinetic Energy

nghUs; xd;W ,aq;Fk; NghJ mjd; ,af;fk; fhuzkhf nfhz;Ls;s rf;jp ,af;fg;ghl;L rf;jp MFk;.

m jpzpTs;s nghUs; v fjpapy; ,aq;Fk; NghJ mjpYs;s ,af;fg;ghl;L rf;jp My; jug;gLk;.

ngaHT ,af;fg;ghl;L rf;jp

2

2

1. mvEK

m v

02

mOj;j rf;jp Potential Energy

nghUspd; epiy fhuzkhf Nrkpf;fg;gLk; rf;jp mOj;j rf;jp MFk;. ,J gpd;tUkhW tifg;gLj;jg;gLk;. i. <Hg;G mOj;j rf;jp (Gravitational potential energy) ii. kPspay; mOj;j rf;jp (Elastic potential energy)

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

<Hg;Gg; Gyj;jpy; m jpzpTs;s nghUs; h cauj;jpw;F caHj;Jk; NghJ Nrkpf;fg;gLk; rf;jpahdJ mOj;j rf;jp khw;wkhFk;. mOj;j rf;jp khw;wk; My; jug;gLk;. mghEP .

i. <Hg;G mOj;j rf;jp (Gravitational potential energy)

ii. kPspay; mOj;j rf;jp (Elastic potential energy)

tpfpjrk vy;iyf;F cl;gl;l epiyapy; gpuNahfpf;fg;gLk; tpirahdJ mjpy; Vw;gLk; ePl;rp my;yJ RUf;fj;jpw;F NeHtpfpjrkdhFk;.

Cf;fpd; tpjp (Hook’s Law)

x

F

rhjhuz epiy

(gpuNahfpf;fg;gl;l tpir)

FeEP2

1.

Muk;g epiyapy; ,Ue;J tpw;RUshdJ X ePl;rpaile;j epiyapy; tpw;RUspy; nraw;gLk; tpir F Mapd;

MFk;.

mjhtJ

,q;F k - tpy;ypd; tpir khwpyp vdg;gLk;.

RUsptpw;fs;> kPspay; nghUl;fs; Nghd;wtw;wpy; Nrkpf;fg;gLk; kPspay; rf;jpahdJ

my;yJ My; jug;gLk;.

,q;F k - tpy; khwpyp / tpir khwpyp vdg;gLk;.

e - ePl;rp / RUf;fk;

xF

kxF

2

2

1. keEP

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

rf;jpf; fhg;G jj;Jtk; (Principle of Conservation of energy)

rf;jpia Mf;fNth> mopf;fNth KbahJ. Mdhy; mij xU tifapy; ,Ue;J ,d;ndhU tiff;F khw;wyhk;. ve;j khw;wj;jpd; NghJk; njhFjpapd; nkhj;j rf;jp khwhJ ,Uf;Fk;

nghwpKiw rf;jpf; fhg;G jj;Jtk; (Principle of Conservation of mechanical energy)

nkhj;j nghwpKiw rf;jp = ,af;fg;ghl;L rf;jp + mOj;j rf;jp

gpd;tUk; ,af;fq;fspy; tspj; jil Gwf;fzpf;fg;gbd; nghwpKiw rf;jp fhf;fg;gLk;.

i) vspa Crypd; ,af;fk;.

ii) RUsp tpy;ypy; njhq;ftplg;gl;l Rikapd; epiyf;Fj;J ,af;fk;.

iii) GtpaPHg;gpd; fPo; ,af;fk;.

EPEKEM ...

Ntiy rf;jpj; jj;Jtk;

Gw tpirf;F vjpuhf Ntiy nra;ag;gLkhapd;

Gw tpirapdhy; nra;ag;gl;l Ntiy

cuha;Tf;F vjpuhf nra;ag;gl;l Ntiy = +

K.E + P.E ,y; Vw;gl;l mjpfupg;G

Gw tpirf;F vjpuhf nra;ag;gl;l Ntiy

cuha;Tf;F vjpuhf nra;ag;gl;l Ntiy = +

(K.E + P.E) ,y; Vw;gLk; FiwT

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

Note : -

nghJthf jiu kl;lk;> Crypd; mjpjho; Gs;sp vd;gd mOj;j rf;jp g+r;rpa kl;lkhf fUjg;gLk;.

vdpDk; re;jHg;gq;fSf;F Vw;g khWgLk;.

epiy A apy; nkhj;j nghwpKiw rf;jp

epiy B apy; nkhj;j nghwpKiw rf;jp

A B cgNahfpf;f

MfNt

,af;fg;ghl;L rf;jp + mOj;j rf;jp = khwpyp MFk;

2

112

1mvmghEA

2

222

1mvmghEB

asuv 222

)(2 21

2

1

2

2 hhgvv

AE

mvmgh

hhgvmmgh

mvmgh

2

11

21

2

12

2

22

2

1

))(2(2

1

2

1BE

A

B h1

h2

v1

v2

ZPL (jiu) g+r;rpa rf;jp kl;lk;

GtpaPHg;gpd; fPo; RahjPdkhf tpOk; nghUs; xd;wpy;

nghwpKiw rf;jpf; fhg;G jj;Jtk;

juk; - 12, 13

njhFg;G : jpU S. fhz;Bguh[h> Mrpupau; - ngsjpftpay; (ah/aho; ,e;J kfspH fy;Y}up> aho;g;ghzk;)

fzpdp tbtikg;G : jpU.k.epjH\d;> MrpupaH - jfty; njhlHghly; njhopDl;gk;> (ah/`hl;ypf; fy;Y}up> gUj;jpj;Jiw)

tY (Power)

tYtpd; myF J s-1 = W (watt)

tYtpd; gupkhzk; ML2T -3

Ntiy XH vz;zpf; fzpakhFk;.

Ntiy nra;Ak; tPjk; / XuyF Neuj;jpy; nra;ag;gl;l Ntiy tY vdg;gLk;. mjhtJ rf;jp ntspaplg;gLk; tPjk; tY vdg;gLk;.

tY = ————— Neuk;

Ntiy

t

WP

tY = ———–——————— Neuk;

tpir X ,lg;ngaHr;rp

tY = tpir X Ntfk;

P = F X v