Jawaban 1731130017 Dhetax Erbian Pujangga
Jawaban soal no 1
Vektor perpindahan (2,2) ke (6,5)
R = ( Xujung – Xpangkal)i
+ ( Yujung – Ypangkal)j
= ( 6 – 2) i + ( 5 – 2 ) j
= 4i +3j
Jarak Perpindahan
R = √(42
+ 32)
= √(9 +16 )
= √25
= 5
Jawaban soal no 2
A = 4i + 3j + 2k
B = -4i + 2j
A x B =
(4i + 3j + 2k) x ( -4i + 2j)
=
(4i x (-4i)) + (4i x 2j) + (3j x (-4i)) + (3j x 2j) + (2k x (-4i)) + (2k x 2j)
= 0 + 8k + 12k + 0 + (-8j) + (-4i)
=
-4i -8j + 20k
A . B =
(4i + 3j + 2k) x ( -4i + 2j)
=
(4i x (-4i)) + (4i x 2j) + (3j x (-4i)) + (3j x 2j) + (2k x (-4i)) + (2k x 2j)
= -16 + 0 + 0 + 6 + 0 + 0
=
-10