RUMUS-RUMUS FISIKA SMP NO
RUMUS
1
Massa Jenis m ρ= V
2
Pemuaian panjang zat paat ∆ = o.α .∆T
t = o + ∆
SIMBOL
ρ = massa jenis m = massa v = volum
= ∆
pertambahan panjang o = panjang mula-mula α = koefisien koefisien muai zat padat ∆T = perubahan suhu t = panjang akhir
3
!a#$% a. Kalor untuk menaikan suhu benda ! = m"c"#$ b. Kalor untuk merubah wujud benda ! = m"%
! = *alo+ m = massa c = *alo+ jenis % = *alo *alo++ late laten n &*al &*alo+ o+ ua, ua, *alo+ emun, *alo+ e*u, e*u, *alo+ leu+'
SATUAN (SI) Kg/m3 Kg m3
m m /oC atau /K o C m
oule Kg /KgoC /*g
c. Asas Bl Black m1"c1"&$1-$c' = m2"c2"&$c-$ 2'
(" )lat )lat Pema Pemana nas s P .t = m.c.∆T Ge%a& Lu%us Be%atu%an s = v"t
P = (aa alat emanas t = .a*t .a*tu u untu untu* * mena menai* i*an an suu s = ja+a* v = *eceatan t = .a*tu
.att se*on M m/s s
INFORMASI PENTING 1 g/cm3 =1000 Kg/m3 1 Kg/m3 = 0,001 g/cm3
!"usus agian ini ∆ dan o tidak
harus dalam meter asalkan satuan keduanya sama misal dalam cm 1 *alo+i = ,2 oule 1 oule = o,2 *alo+i
$1$2 &en(a ang memunai suu lei (ileta**an (i +uas *i+i' 1 *m/jam = 1 4
9
Ge%a& Lu%us Be%u'a" Be%atu%an 6t = vo7at 6t2 = vo2 7 2as S = vot7&1/2'a"t2 Gaa : = m"a Be%at . = m"g
vo = *eceatan a.al 6t = *eceatan a*i+ a = e+ceatan t = .a*tu s = ja+a* : = gaa m = massa a = e+ceatan . = e+at g = e+ceatan g+avitasi
m/s m/s m/s2 se*on m ;e.ton *g m/s2 ; m/s2
<
Te&anan at Paat F p = A
= te*anan : = gaa ) = luas e+mu*aan i(ang
Pascal &Pa' ; m2
Te&anan at *ai%
ρ = massa jenis cai+an g = e+ceatan g+avitasi = *e(alaman >at cai+ :1 = gaa a(a enamang 1 :2 = gaa a(a enamang 2 )1 = %uas enamang 1 )2 = %uas enamang 2
Kg/m3 m/s2 m ; ; m
p
. g .h = ρ
Sistem i(+oli* F 1 F A1
=
A
Gaa apung + gaa
18
m/s 1 m/s = 1 4
5
5
18 5
m/s Untu* e+lamatan e+lamatan a e+nilai negati8
esa+na massa selalu teta, namun e+at te+gantung e+ceatan g+avitasi (i mana en(a ts e+a(a 1 Pa = 1 ;/m 2
Sistem i(+oli* (iali*asi*an (iali*asi*an a(a mesin engang*at moil seingga ean ang e+at (aat (iang*at (engan gaa ang lei *ecil, satuan
1
&e atas :) = .u ? .8
:) = @aa *e atas .u= e+at en(a (itimang (i u(a+a .8 = e+at en(a (alam cai+an
:) = !"6"g
; ; ;
!"6"g me+ua*an
6 = volum >at cai+ ang (iin(a*an
A
10
Te&anan gas paa %uang te%tutup P1"61 = P2"62 Ene%gi p$tensia# B = m"g"
P = $e*anan 6 = 6olume gas
atm m3
m = massa g = e+ceatan g+avitasi = *etinggian
*g m/s2 m
v = *eceatan
m/s
Ene%gi !ineti& 1
B* =
11
mv2
Pesawat Sederhana
Pengung&it ." . = :" : Keuntungan me*anis Pengung*it w F KM = = w F !at%$# w KM = F w Bg Mi%ing KM = F = 12
Pa(a saat ua *elaa jatu (a+i oon, ua mengalami e+uaan entu* ene+gi (a+i ene+gi otensial menja(i ene+gi *ineti* Pa(a ta*al / sistem *at+ol, esa+na KM (itentu*an ole jumla ana* tali ang menanggung ean atau iasana sama (engan jumla *at+ol (alam sistem ts"
. = e+at ean : = gaa / *uasa . = lengan ean : = lengan *uasa KM = *euntungan me*anis s = anjang i(ang mi+ing = tinggi i(ang mi+ing (a+i e+mu*aan tana
; ; m m m m
8 = 8+e*uensi geta+an / gelomang $ = e+io(e geta+an / gelomang n = jumla geta+an / gelomang v = ceat +amat gelomang anjang &satu' λ = gelomang
e+t> se*on m/s m
e+t> = 1/se*on
( = *e(alaman v = ceat +amat gelomang uni t = selang .a*tu anta+a sua+a &atau sona+' (i*i+im samai (i(enga+ / (ite+ima *emali 8 = ja+a* 8o*us ce+min R = ja+i-ja+i *eleng*ungan ce+min So = ja+a* en(a (i (ean ce+min Si = ja+a* aangan (a+i ce+min i = $inggi aangan o = $inggi en(a M = Pe+esa+an
m m/s se*on
Rumus ini (aat (iguna*an untu* mengu*u+ *e(alaman ai+ atau *e(alaman gua"
cm cm cm cm cm cm
! ce+min ce*ung &7' ! ce+min cemung &-' Si &7'=aangannat a Si &-'=aangan maa
h
Geta%an
n
1
=
t T 1 t $ = = f n Ge#$m'ang . f v = λ
Buni (=
1
e+at >at cai+ ang (iin(a*an en(a *eti*a en(a (icelu*an *e (alam suatu cai+an Suu gas (iangga teta
s
8=
13
)1 a+us sama (engan )2 (an satuan :1 a+us sama (engan : 2
v.t
*a"aa Cermin Lengkung (cekung dan cembung)
f = 1
f M
1
=
=
R
1
So Si So
+
1
Si
=
Hi Ho
enentukan si!at
- &*ai'
M 1 a (ie+esa+ M = 1 a sama esa+
ba"angan cermin cekung
Pa(a ce+min ce*ung D
Ruang en(a7Ruang a = 5
III
II
I
I, R
-
1
f 1
f M
+
So
=
Si So
Si Hi Ho
O
EE
EEE
EEE
EE
teat (i R teat (i 8
teat (i R teat (i 8
maa, tega*, (ie+esa+ nata, te+ali*, (ie+esa+ nata, te+ali*, (ie+*ecil nata, te+ali*, sama esa+ ti(a* te+entu* aangan
:2 ? 2:2 2:2
(de#an) ( belakang' .F. F.
E6
Ruan g en( a F-:2
1
=
Si8at aangan
F/
M G 1 a (ie+*ecil
(iot+i
P = *e*uatan lensa 8 = ja+a* 8o*us lensa Pa(a lensa cemung D
1
=
Ruang aanga n
O
Lensa (cekung dan cembung) P =
Ruan g en( a E
.F/
teat (i :2
Ruang aanga n
Si8at aangan
(i (ean lensa (i *anan 2:1 2:1
maa, tega*, (ie+esa+ nata, te+ali*, (ie+esa+ nata, te+ali*, sama esa+ -
-
aangan ang (ientu* ce+min cemung se#a#u e+si8at D ma"a$ tegak$ di#erkecil
Untu* menca+i *e*uatan lensa, ja+a* 8o*us a+us (alam mete+ ! lensa cemung &7' ! lensa ce*ung &-' Si &7'=aangannat a Si &-'=aangan maa M 1 a (ie+esa+ M = 1 a sama esa+ M G 1 a (ie+*ecil
15
A#at Opti& a0 Lup Ma1
5 cm
f
+1
5 cm
Mt1
f '0 Mi&%$s&$p M = 8 o 4 8 o*
19
I =
1<
- &*ali' cm cm
6 = e(a otensial H = ene+gi list+i* ! = muatan list+i* R = amatan
volt joule coulom om&I'
! = amatan jenis
A
enganta+
Im m m2
k .Q1Q d
Q
= ρ
- &*ali'
; ;m2/c2 coulom m ame+e se*on
t List%i& 2inamis W V = Q %ukum Coulomb 6 = E"R amatan Penganta+
R
M = Pe+esa+an Mi*+os*o 8 o = 8o*us lensa oe*ti8 8 o* = 8o*us lensa o*ule+
- &*ali'
: = gaa coulom * = *onstanta coulom ! = muatan list+i* ( = ja+a* anta+ muatan E = a+us list+i* t = .a*tu
List%i& Statis
F =
Ma = Pe+esa+an untu* mata e+a*omo(asi ma*simum Mt = Pe+esa+an untu* mata ti(a* e+a*omo(asi / +ile*s 8 = 8o*us lu
= anjang *a.at
aangan ang (ientu* lensa ce*ung se#a#u e+si8at D ma"a$ tegak$ di#erkecil %ensa o*ule+ me+ua*an lensa ang e+a(a (i (e*at mata engamat %ensa oe*ti8 e+a(a (i (e*at oe* ang (iamati
"
) = %uas enamang enganta+
&angkaian Seri & Rt = R17R27""""7Rn &angkaian 'aralel & 1
1
=
+
1
+ .... +
1
Rt R1 R Rn &angkaian 'aralel terdiri dari &esistor Rt =
R1 xR R1
%ukum Kircho!! ΣE masu* = ΣE *elua+ &angkaian Listrik dengan hambatan dalam a" ate+ai Se+i n.Ε I = n.r + R " ate+ai Pa+alel
I =
1
E = *uat a+us
n = jumla elemen B = @@% &gaa ge+a* list+i*' + = amatan (alam sume+ tegangan R = amatan lua+ total
6olt om om
@@% me+ua*an e(a otensial ate+ai ang (iitung saat +ang*aian te+u*a atau e(a otensial asli ate+ai
E r + R n
Ene%gi List%i& an 2aa List%i& a. *nergi Listrik H = !"6 H = 6"E"t H = E2Rt H=
ame+e
+ R
V t R
H = Bne+gi %ist+i* ! = Muatan %ist+i* 6 = tegangan / e(a otensial E = Kuat )+us %ist+i* P = Jaa %ist+i* t = .a*tu
joule coulom volt ame+e .att se*on
i *alo+i ? ,2 oule E = 0,2 *al
b. +a"a Listrik P = 6"E P= E2R P= P=
V R W
t
1A
Gaa L$%entz : = "i"
20
T%ans-$%mat$% Np Vp =
Ns Vs Vp Is = Vs Ip Is Np = Ip Ns *!isiensi ,rans!ormator
: = @aa %o+ent> = Kuat me(an magnet i = *uat a+us list+i* = anjang *a.at 6 = tegangan +ime+ / masu*an 6s = teg" Se*un(e+ / *elua+an E = )+us +ime+ / masu*an Es = )+us se*un(e+ / *elua+an ; = jumla lilitan +ime+ ;s = umla lilitan se*un(e+ Hs = Bne+gi *elua+an H = Bne+gi masu*an Ps = Jaa *elua+an
; $esla ) m 6 6 ) ) .att .att
#
η = η =
Ws Wp Ps Pp
x1%% $
P = Jaa masu*an
x1%% $
5