Page 43 - MUDAH DAN AKTIF BELAJAR FISIKA SMA KELAS X

Q Q V V
V 2 4
3
V
3
V
R 5
V
1 V
6
V R V 2
P P V 6
O O 4
Gambar 2.6 V V
Resultan dua buah vektor R = P + Q 5 Gambar 2.7 1
dilukis dengan metode poligon.
Resultan enam buah vektor R = V + V + V + V + V + V
b dilukis dengan metode poligon. 1 2 3 4 5 6
b. Selisih Vektor
"/=9./ B+81 .31>8+5+8 .+6+7 7/6>53< </63<32 .>+ ?/5=9; <+7+ ./81+8
7/=9./ B+81 .31>8+5+8 >8=>5 :/84>76+2+8 ?/5=9; '/63<32 .>+ ,>+2 ?/5=9;
.+8 ! .+:+= .3=>63< " E ! +=+> ;/<>6=+8 ?/5=9; .+8 ?/5=9; E!
a +.+6+2 " E! )8=>5 7/6>53< ?/5=9; " E! :/;=+7+ ?/5=9;
O
O .36>53< </6+84>=8B+ ?/5=9; E! +;+8B+ <+7+ </:/;=3 7/6>53< :/84>76+2+8
a
?/5=9; :/;2+=35+8 ?/5=9; E! 7/;>:+5+8 ?/5=9; ! ./81+8 +;+2 ,/;6+@+8+8
c b .+:>8 ?/5=9; +.+6+2 ?/5=9; B+81 7/812>,>815+8 :+815+6 ?/5=9;
5/ >4>81 ?/5=9; E! %/;2+=35+8 +! /
c = a – b
3. Rumus untuk Menentukan Besar dan Arah Resultan Dua
Gambar 2.8
Resultan selisih vektor c = a – b. Buah Vektor
&/<>6=+8 .>+ ,>+2 ?/5=9; .+:+= .3-+;3 ./81+8 7/811>8+5+8 ;>7><
L M %/;2+=35+8 +! /
"/8>;>= +=>;+8 -9<38>< .+;3 </13=31+ $ " .3:/;96/2 :/;<+7++8
$" $ " E $ " -9< E

V R
2 $" $ " E $ " E-9<

1 $" $ " $ " -9<

180 –
2 $6/2 5+;/8+ $" <+7+ ./81+8 $ <+7+ ./81+8 .+8 $! <+7+

./81+8 7+5+ :/;<+7++8 =/;</,>= 7/84+.3
O
V K

1 -9<
Gambar 2.9
Resultan dua vektor
- 9 < E
b
./81+8 +.+6+2 <>.>= +:3= B+81 .3,/8=>5 +8=+;+ ?/5=9; .+8 ?/5=9;

;+2 ;/<>6=+8 ?/5=9; .+:+= .3=/8=>5+8 7/811>8+5+8 +=>;+8 <38>< </,+1+3
,/;35>=

E
<38 <38 <38
a
O
b R 35+ .>+ ,>+2 ?/5=9; +8=+;+ ?/5=9; B+81 <+=> .+8 ?/5=9; B+81

6+38 <+6381 =/1+5 6>;>< ?/5=9; ;/<>6=+88B+ .+:+= .3</6/<+35+8 ./81+8

.+636 $ %/;2+=35+8 +! /
/<+;8B+ ?/5=9; ;/<>6=+8 +.+6+2
E
a
O
Gambar 2.10 Contoh 2.1
Dua buah vektor saling tegak lurus.
>+ ,>+2 ?/5=9; 1+B+ .+8 7+<381 7+<381 ,/<+;8B+ # .+8 # .+8 7/736353

=3=35 :+815+6 ,/;37:3= 3=>816+2 836+3 .+8 +;+2 ;/<>6=+8 ?/5=9; 383 435+ <>.>= +:3=
+8=+;+ 5/.>+ ?/5=9; =/;</,>= +.+6+2 C
34 Mudah dan Aktif Belajar Fisika untuk Kelas X