Question

3. Dois vetores são dados por:
a = (4,0m)i – (3,0m)j + (1,0,)k
b = (-1,0m)i + (1,0 m)j + (4,0)k.
Determine em termos de vetores unitários, (a) a + b; (b) a – b; (c) um terceiro vetor, c, tal que a – b + c = 0

Answer 1

a) a+b= (4,0m +(-1,0m))î + (-3,0m + 1,0m)j + (1,0m +4,0m)k
         = (3,0m)î - (2,0m)j + (5,0m)k

b) a-b= (4,0m -(-1,0m))î + (-3,0m - 1,0m)j + (1,0m - 4,0m)k
        = (5,0m)î - (4,0m)j - (3,0m)k

c) a-b+c=0
   c= -a+b 
   c= (-4,0m +(-1,0m))î + (3,0m + 1,0m)j + (-1,0m + 4,0m)k
     = (-5,0m)î + (4,0m)j + (3,0m)k