Question

how do you do this?!

A vector has a magnitude of 12 and a direction of 80°. Write the vector in terms of unit vectors.
a) 3.4i + 0.6j
b) 11.8i + 2.1j
c) 2.1i + 11.8j
d) 0.6i + 3.4j

Answer 1

every vector has a horizontal component and vertical component
from trig, remember cos refers to horizontal while sin refers to vertical

--> 12cos(80) + 12sin(80)

Answer 2

omg thank you!

Answer 3

it's easier than it seems :)

Answer 4

i have one more question though. could you help?

Answer 5

your welcome...sure go ahead

Answer 6

Find | |U + V| | given the vectors U = <0, 4> and V = <3, -5>.
a)
b) 3
c) 10
d) 2

Answer 7

i just dont know what to do when it's in brackets.

Answer 8

the brackets or double lines refers to magnitude
first find vector U + V --> just add the components
then find magnitude by taking sum of squared components , its just like pythagorean thm
example: vector = < 3,4>
||v|| = sqrt(3^2 + 4^2) = 5

Answer 9

ah okay. so it's 5. thank you

Answer 10

wait now

Answer 11

no it's not 5

Answer 12

haha no that was an example :)

Answer 13

hahahaha okay hold on let me work out that problem :)

Answer 14

okay i got sqrt10

Answer 15

i have another question. is that okay? it's the last one sorry